Pub Date : 2026-01-12DOI: 10.1016/j.jlumin.2026.121755
Wanjia Wang , Lixia Jing , Yanqing Zu , Kangmin Yang , Run Gan , Yue Peng , Decui Gong , Peitao Liu , Xiaodong Li , Zhaoxin Wu , Ailing Feng
Metal halide perovskite quantum dots (PQDs) have emerged as promising emissive materials for next-generation light-emitting diodes due to their exceptional properties, including high luminescence efficiency, facile spectral tunability, high colour purity and cost-effective solution processability. The organic ligands such as long-chain alkyl acids and amines are traditionally used in the synthesis of PQDs, which enable to effectively passivate the surface defects and maintain the colloidal stability. However, these insulating long-chain ligands will hinder the charge transport within PQDs films and weaken the performance of perovskite quantum dots light-emitting diodes (PeQLEDs). In this review, some highly conductive reagent like conjugated or short-chain organic ligands, inorganic and hybrid ligands that enhance the efficiency of PeQLEDs were summarized. Finally, current challenges and future perspectives of PQDs are outlined, emphasizing the potential of advanced ligand design in achieving high-performance optoelectronic devices.
{"title":"Highly conductive ligands resurfacing perovskite quantum dots boost the efficiency of light-emitting diodes","authors":"Wanjia Wang , Lixia Jing , Yanqing Zu , Kangmin Yang , Run Gan , Yue Peng , Decui Gong , Peitao Liu , Xiaodong Li , Zhaoxin Wu , Ailing Feng","doi":"10.1016/j.jlumin.2026.121755","DOIUrl":"10.1016/j.jlumin.2026.121755","url":null,"abstract":"<div><div>Metal halide perovskite quantum dots (PQDs) have emerged as promising emissive materials for next-generation light-emitting diodes due to their exceptional properties, including high luminescence efficiency, facile spectral tunability, high colour purity and cost-effective solution processability. The organic ligands such as long-chain alkyl acids and amines are traditionally used in the synthesis of PQDs, which enable to effectively passivate the surface defects and maintain the colloidal stability. However, these insulating long-chain ligands will hinder the charge transport within PQDs films and weaken the performance of perovskite quantum dots light-emitting diodes (PeQLEDs). In this review, some highly conductive reagent like conjugated or short-chain organic ligands, inorganic and hybrid ligands that enhance the efficiency of PeQLEDs were summarized. Finally, current challenges and future perspectives of PQDs are outlined, emphasizing the potential of advanced ligand design in achieving high-performance optoelectronic devices.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121755"},"PeriodicalIF":3.6,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-08DOI: 10.1016/j.jlumin.2026.121753
Jiarong Zhao , Yuan-Hao Zhu , Lin Zhang , Rongqiao Wan , Zhaozhen Wang , Qimiao Chen , Shaoteng Wu , Chuan Seng Tan , Jun-Wei Luo
The Ge1-xSnx alloy is a promising candidate for silicon-based optoelectronic devices, yet few experimental studies have investigated its full indirect-to-direct bandgap transition behavior. The photoluminescence (PL) characteristics of Ge1-xSnx films with Sn compositions of 3.3 %, 6.5 %, 10.3 %, and 12.8 % were investigated by a high-resolution and wide spectrum (1∼5.5 μm) Fourier Transform Infrared Spectrometer PL system. Owing to the wide spectrum measurement capability, the PL spectra of these Ge1-xSnx films can be compared in a single system. It can be seen that the PL spectrum of the high-Sn content GeSn film (12.8 %) exhibits a high-energy shoulder peak, which is different from the low-Sn content GeSn film (3.3 %) with a low-energy shoulder peak. By extracting the transition peak position through Gaussian fitting, we observed for the first time that the direct bandgap energy of the high-Sn content GeSn is lower than the indirect bandgap energy, resulting in the negative energy separation. Furthermore, as the Sn content increases, a clear indirect-to-direct transition is observed, which leads to opposite temperature-dependent PL-intensity trends between the high- and low-component GeSn films. Finally, the insensitivity to temperature was demonstrated in GeSn with Sn compositions of 6.5 %, indicating a balance between radiative and non-radiative recombination. These findings provide further evidence of - and -valley inversion and quasi-direct bandgap GeSn materials, indicating great potential for direct bandgap GeSn and GeSn based optoelectronic devices grown on Si.
{"title":"Systematic investigation of photoluminescence characteristics in GeSn films with varied Sn content by high-resolution and wide-spectrum system","authors":"Jiarong Zhao , Yuan-Hao Zhu , Lin Zhang , Rongqiao Wan , Zhaozhen Wang , Qimiao Chen , Shaoteng Wu , Chuan Seng Tan , Jun-Wei Luo","doi":"10.1016/j.jlumin.2026.121753","DOIUrl":"10.1016/j.jlumin.2026.121753","url":null,"abstract":"<div><div>The Ge<sub>1-x</sub>Sn<sub>x</sub> alloy is a promising candidate for silicon-based optoelectronic devices, yet few experimental studies have investigated its full indirect-to-direct bandgap transition behavior. The photoluminescence (PL) characteristics of Ge<sub>1-x</sub>Sn<sub>x</sub> films with Sn compositions of 3.3 %, 6.5 %, 10.3 %, and 12.8 % were investigated by a high-resolution and wide spectrum (1∼5.5 μm) Fourier Transform Infrared Spectrometer PL system. Owing to the wide spectrum measurement capability, the PL spectra of these Ge<sub>1-x</sub>Sn<sub>x</sub> films can be compared in a single system. It can be seen that the PL spectrum of the high-Sn content GeSn film (12.8 %) exhibits a high-energy shoulder peak, which is different from the low-Sn content GeSn film (3.3 %) with a low-energy shoulder peak. By extracting the transition peak position through Gaussian fitting, we observed for the first time that the direct bandgap energy of the high-Sn content GeSn is lower than the indirect bandgap energy, resulting in the negative energy separation. Furthermore, as the Sn content increases, a clear indirect-to-direct transition is observed, which leads to opposite temperature-dependent PL-intensity trends between the high- and low-component GeSn films. Finally, the insensitivity to temperature was demonstrated in GeSn with Sn compositions of 6.5 %, indicating a balance between radiative and non-radiative recombination. These findings provide further evidence of <span><math><mrow><mi>Γ</mi></mrow></math></span>- and <span><math><mrow><mi>L</mi></mrow></math></span>-valley inversion and quasi-direct bandgap GeSn materials, indicating great potential for direct bandgap GeSn and GeSn based optoelectronic devices grown on Si.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121753"},"PeriodicalIF":3.6,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-08DOI: 10.1016/j.jlumin.2026.121735
Erdem Uzun , Zehra Özdemir , Esra Özturk
Thermoluminescence properties of aluminate based persistent luminescence phosphors such as Sr3Al2O6:Eu3+,Ho3+, Sr2.99Ba0.01Al2O6:Eu3+,Ho3+, Sr2.99Mg0.01Al2O6:Eu3+,Ho3+, Ba3Al8O15:Eu3+,Dy3+, Ca3Al8O15:Eu3+,Dy3+, and Mg3Al8O15:Eu3+,Dy3+ were investigated. Natural thermoluminescence emission, reusability, the effects of alpha-beta irradiation on the glow curve, and fading properties were analysed. Peak position, variable dose and glow curve fitting methods were applied to the phosphors and fundamental trapping parameters were calculated. Phosphors were irradiated up to the saturation dose level, and the concentrations of electron traps were measured experimentally. An energy-band configuration containing 7 active electron traps, corresponding to the 7 TL peaks observed experimentally, has been proposed to explain the theoretical TL glow curve in the materials. The phosphors show a natural thermoluminescence emission; however, this disappears following a heating treatment. The glow curves of the phosphors have seven distinct glow peaks and many low and high-temperature satellite maximums. It was observed that the individual TL peaks originate from the Eu-doped alumina, and Sr, Ba, Ca, Dy and Ho impurities did not change the individual peak temperatures of the matrix material or produce a new glow peak. However, the peak intensities are highly sensitive to the presence of dopants. It has been observed that alpha radiation affects relatively shallow electron traps more strongly, resulting in the TL glow peaks appearing at lower temperatures. The phosphors show both normal and abnormal fading characteristics during both short-term and long-term storage.
{"title":"Thermoluminescence properties of some aluminate based persistent luminescence phosphors","authors":"Erdem Uzun , Zehra Özdemir , Esra Özturk","doi":"10.1016/j.jlumin.2026.121735","DOIUrl":"10.1016/j.jlumin.2026.121735","url":null,"abstract":"<div><div>Thermoluminescence properties of aluminate based persistent luminescence phosphors such as Sr<sub>3</sub>Al<sub>2</sub>O<sub>6</sub>:Eu<sup>3+</sup>,Ho<sup>3+</sup>, Sr<sub>2.99</sub>Ba<sub>0.01</sub>Al<sub>2</sub>O<sub>6</sub>:Eu<sup>3+</sup>,Ho<sup>3+</sup>, Sr<sub>2.99</sub>Mg<sub>0.01</sub>Al<sub>2</sub>O<sub>6</sub>:Eu<sup>3+</sup>,Ho<sup>3+</sup>, Ba<sub>3</sub>Al<sub>8</sub>O<sub>15</sub>:Eu<sup>3+</sup>,Dy<sup>3+</sup>, Ca<sub>3</sub>Al<sub>8</sub>O<sub>15</sub>:Eu<sup>3+</sup>,Dy<sup>3+</sup>, and Mg<sub>3</sub>Al<sub>8</sub>O<sub>15</sub>:Eu<sup>3+</sup>,Dy<sup>3+</sup> were investigated. Natural thermoluminescence emission, reusability, the effects of alpha-beta irradiation on the glow curve, and fading properties were analysed. Peak position, variable dose and glow curve fitting methods were applied to the phosphors and fundamental trapping parameters were calculated. Phosphors were irradiated up to the saturation dose level, and the concentrations of electron traps were measured experimentally. An energy-band configuration containing 7 active electron traps, corresponding to the 7 TL peaks observed experimentally, has been proposed to explain the theoretical TL glow curve in the materials. The phosphors show a natural thermoluminescence emission; however, this disappears following a heating treatment. The glow curves of the phosphors have seven distinct glow peaks and many low and high-temperature satellite maximums. It was observed that the individual TL peaks originate from the Eu-doped alumina, and Sr, Ba, Ca, Dy and Ho impurities did not change the individual peak temperatures of the matrix material or produce a new glow peak. However, the peak intensities are highly sensitive to the presence of dopants. It has been observed that alpha radiation affects relatively shallow electron traps more strongly, resulting in the TL glow peaks appearing at lower temperatures. The phosphors show both normal and abnormal fading characteristics during both short-term and long-term storage.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121735"},"PeriodicalIF":3.6,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.jlumin.2026.121752
Dejian Hou , Jianhong Dong , Rui Huang , Huihong Lin , Shaomin Lin , Yi Zhang , Zhenxu Lin , Huan Yang , Hailong Liu , Jinyan Li
Multiple-emission phosphors, which can be engineered via co-doping strategies and energy transfer regulation, have become a research hotspot in recent years. In this research, Mn2+ and Cr3+ doped Sr2MgAl22O36 phosphors were prepared using a high-temperature solid-state reaction method. The green light emission of Mn2+ and the deep-red emission of Cr3+ were investigated, and the impacts of doping concentration and temperature were discussed in detail. Dual-band emission can be achieved for co-doped samples under blue light excitation, and the energy transfer from Mn2+ to Cr3+ was confirmed. Owing to the distinct temperature responses of Mn2+ and Cr3+, optical temperature sensing properties were demonstrated for the co-doped sample, which may offer a feasible approach for non-contact temperature measurement. Moreover, a triple-emission phosphor-converted light-emitting diode (pc-LED) device was fabricated, highlighting the potential application of Sr2MgAl22O36:Mn2+,Cr3+ in plant growth.
{"title":"Luminescence properties, energy transfer, and potential applications of Sr2MgAl22O36:Mn2+,Cr3+ phosphor","authors":"Dejian Hou , Jianhong Dong , Rui Huang , Huihong Lin , Shaomin Lin , Yi Zhang , Zhenxu Lin , Huan Yang , Hailong Liu , Jinyan Li","doi":"10.1016/j.jlumin.2026.121752","DOIUrl":"10.1016/j.jlumin.2026.121752","url":null,"abstract":"<div><div>Multiple-emission phosphors, which can be engineered via co-doping strategies and energy transfer regulation, have become a research hotspot in recent years. In this research, Mn<sup>2+</sup> and Cr<sup>3+</sup> doped Sr<sub>2</sub>MgAl<sub>22</sub>O<sub>36</sub> phosphors were prepared using a high-temperature solid-state reaction method. The green light emission of Mn<sup>2+</sup> and the deep-red emission of Cr<sup>3+</sup> were investigated, and the impacts of doping concentration and temperature were discussed in detail. Dual-band emission can be achieved for co-doped samples under blue light excitation, and the energy transfer from Mn<sup>2+</sup> to Cr<sup>3+</sup> was confirmed. Owing to the distinct temperature responses of Mn<sup>2+</sup> and Cr<sup>3+</sup>, optical temperature sensing properties were demonstrated for the co-doped sample, which may offer a feasible approach for non-contact temperature measurement. Moreover, a triple-emission phosphor-converted light-emitting diode (pc-LED) device was fabricated, highlighting the potential application of Sr<sub>2</sub>MgAl<sub>22</sub>O<sub>36</sub>:Mn<sup>2+</sup>,Cr<sup>3+</sup> in plant growth.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121752"},"PeriodicalIF":3.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.jlumin.2025.121694
Lauany Mazzon Pontes , João Vitor Gonçalves de Faria , Julia Santana Reinaldi , Patrícia Paula Araújo Magrin , Natalia Nascimento Silveira , Raquel Alves dos Santos , Lucas Alonso Rocha , Marc Verelst , Eduardo José Nassar
Calcium phosphates (CPs) have been widely used in biomedical applications due to their excellent biocompatibility, crystalline structure, and low toxicity. These characteristics allow structural modifications during synthesis, such as substitution with lanthanide ions, which confer luminescent properties to the matrix. In this study, a CP matrix was synthesized from phosphoric acid and calcium nitrate, with partial substitution of calcium ions by the lanthanide ions erbium (Er3+) and ytterbium (Yb3+) at 1 % and 10 % concentrations, respectively. Characterization by X-ray diffraction revealed a mixture of CP phases. Vibrational spectroscopy in the infrared region identified characteristic matrix bands. Photoluminescence analysis showed bands attributed to Er3+ in the visible and infrared regions. In upconversion energy analyses, using 980 nm laser excitation with power variation between 490 and 1000 mW, more intense emissions were observed in the green region. The increase in power suggested possible thermal excitation of electrons. In temperature variation experiments (25–100 °C), the material demonstrated and confirmed significant thermal sensitivity, indicating potential for application in optical temperature sensing. Cytotoxicity assays indicated no impairment of cell viability at any of the tested concentrations, with behavior similar to the negative control at 24, 48, and 72 h.
{"title":"Luminescent properties OF Er3+ and Yb3+ IONS IN a calcium phosphate matrix","authors":"Lauany Mazzon Pontes , João Vitor Gonçalves de Faria , Julia Santana Reinaldi , Patrícia Paula Araújo Magrin , Natalia Nascimento Silveira , Raquel Alves dos Santos , Lucas Alonso Rocha , Marc Verelst , Eduardo José Nassar","doi":"10.1016/j.jlumin.2025.121694","DOIUrl":"10.1016/j.jlumin.2025.121694","url":null,"abstract":"<div><div>Calcium phosphates (CPs) have been widely used in biomedical applications due to their excellent biocompatibility, crystalline structure, and low toxicity. These characteristics allow structural modifications during synthesis, such as substitution with lanthanide ions, which confer luminescent properties to the matrix. In this study, a CP matrix was synthesized from phosphoric acid and calcium nitrate, with partial substitution of calcium ions by the lanthanide ions erbium (Er<sup>3+</sup>) and ytterbium (Yb<sup>3+</sup>) at 1 % and 10 % concentrations, respectively. Characterization by X-ray diffraction revealed a mixture of CP phases. Vibrational spectroscopy in the infrared region identified characteristic matrix bands. Photoluminescence analysis showed bands attributed to Er<sup>3+</sup> in the visible and infrared regions. In upconversion energy analyses, using 980 nm laser excitation with power variation between 490 and 1000 mW, more intense emissions were observed in the green region. The increase in power suggested possible thermal excitation of electrons. In temperature variation experiments (25–100 °C), the material demonstrated and confirmed significant thermal sensitivity, indicating potential for application in optical temperature sensing. Cytotoxicity assays indicated no impairment of cell viability at any of the tested concentrations, with behavior similar to the negative control at 24, 48, and 72 h.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121694"},"PeriodicalIF":3.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.jlumin.2026.121751
Mahmoud A. Khalifa , Mahmoud Abdelfatah , Mohamed A. Habib , Abdelhamid El-Shaer
Temperature-dependent photoluminescence (TDPL) provides powerful insight into the optical features of semiconductors. In this work, we investigate the impact of solution pH (9–13) on structural, morphological, and photoluminescence (PL) properties of Cu2O micrograins, with a particular focus on how these PL changes are obvious at low temperatures (14 K–290 K). X-ray diffraction and scanning electron microscopy results reveal a pH-induced transition in preferred orientation from (200) to (111) facets, accompanied with morphological evolution from small to large micrograins. TDPL measurements uncover distinct recombination mechanisms; besides the near-band excitonic transitions of Cu2O, two strong emission bands related to relaxed excitons at oxygen and copper vacancies are noticed. At 14 K, the pH 9 sample displays a broad PL emission centered at 748 nm, attributed to oxygen vacancies. In contrast, the pH 13 sample displays two distinct peaks at 680 nm and 849 nm, corresponding to oxygen and copper vacancies, respectively. These defect-related emissions are absent in the room-temperature PL spectra. Furthermore, the activation energies (Ea) of these vacancies, determined using the Arrhenius model, are 29.9 meV for oxygen vacancies in the pH 9 sample, and 19.2 meV (oxygen vacancies) and 39.4 meV (copper vacancies) for the pH 13 sample. These results of correlation thermal PL behavior with structural modulation highlight an effective strategy for tuning the defects in Cu2O and underscore the value of TDPL in resolving emission pathways relevant to tunable optoelectronic applications.
{"title":"Revealing defects in Cu2O microstructures: Temperature-dependent photoluminescence insights from pH-tuned facet engineering Cu2O","authors":"Mahmoud A. Khalifa , Mahmoud Abdelfatah , Mohamed A. Habib , Abdelhamid El-Shaer","doi":"10.1016/j.jlumin.2026.121751","DOIUrl":"10.1016/j.jlumin.2026.121751","url":null,"abstract":"<div><div>Temperature-dependent photoluminescence (TDPL) provides powerful insight into the optical features of semiconductors. In this work, we investigate the impact of solution pH (9–13) on structural, morphological, and photoluminescence (PL) properties of Cu<sub>2</sub>O micrograins, with a particular focus on how these PL changes are obvious at low temperatures (14 K–290 K). X-ray diffraction and scanning electron microscopy results reveal a pH-induced transition in preferred orientation from (200) to (111) facets, accompanied with morphological evolution from small to large micrograins. TDPL measurements uncover distinct recombination mechanisms; besides the near-band excitonic transitions of Cu<sub>2</sub>O, two strong emission bands related to relaxed excitons at oxygen and copper vacancies are noticed. At 14 K, the pH 9 sample displays a broad PL emission centered at 748 nm, attributed to oxygen vacancies. In contrast, the pH 13 sample displays two distinct peaks at 680 nm and 849 nm, corresponding to oxygen and copper vacancies, respectively. These defect-related emissions are absent in the room-temperature PL spectra. Furthermore, the activation energies (E<sub>a</sub>) of these vacancies, determined using the Arrhenius model, are 29.9 meV for oxygen vacancies in the pH 9 sample, and 19.2 meV (oxygen vacancies) and 39.4 meV (copper vacancies) for the pH 13 sample. These results of correlation thermal PL behavior with structural modulation highlight an effective strategy for tuning the defects in Cu<sub>2</sub>O and underscore the value of TDPL in resolving emission pathways relevant to tunable optoelectronic applications.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121751"},"PeriodicalIF":3.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.jlumin.2026.121748
Yassmin Kessentini , Iskandar Chaabane , Kawthar Abid , Ali Ben Ahmed , Habib Feki
Organic-inorganic hybrid materials have the potential of providing excellent properties and promising novel optical properties. This work focuses on the white light emission process of one-dimensional (1D) organic-inorganic perovskite (C12H18N)PbBr3 abbreviated as 4BPP[PbBr3]. Contrary to most organic-inorganic hybrid material, where the organic moieties act as barriers and the inorganic part play the role of quantum well, both organic and inorganic parts in 4BPP[PbBr3] are optically active, giving rise to a strong and large emission band covering a wide range of the visible spectrum that can be seen even with the naked eye at room temperature. The photoluminescence spectrum is composed of three bands located at 490 nm (P1), 550 nm (P2) and 600 nm (P3). The first and the second bands are attributed respectivelyto and intra-molecular charge transfer transition within the 4BPP organic cation whereas the third band is related to the inorganic Wannier exciton confined in lead bromide PbBr3 chains. This result was supported by density functional theory calculation. Moreover, the temperature dependence of the PL emission for each transition reveals a different behaviour. In fact, a negative thermal quenching (NTQ) is observed for P1 evolution at low temperature. This NTQ emission is interpreted in terms of transitions between excitonic states involving an exciton-phonon interaction. The P2 observed emission behavior is explained by a charge carrier transfer mechanism between two quantum dots population and the P3 temperature quenching was explained by an increased level of non radiative recombination caused by the phonon vibration (80 cm−1) which corresponds well to Pb-Br stretching vibration observed in Raman spectra.
{"title":"Temperature dependence of Quasi-white-light emission in one-dimensional hybrid material (C12H18N)PbBr3","authors":"Yassmin Kessentini , Iskandar Chaabane , Kawthar Abid , Ali Ben Ahmed , Habib Feki","doi":"10.1016/j.jlumin.2026.121748","DOIUrl":"10.1016/j.jlumin.2026.121748","url":null,"abstract":"<div><div>Organic-inorganic hybrid materials have the potential of providing excellent properties and promising novel optical properties. This work focuses on the white light emission process of one-dimensional (1D) organic-inorganic perovskite (C<sub>12</sub>H<sub>18</sub>N)PbBr<sub>3</sub> abbreviated as 4BPP[PbBr<sub>3</sub>]. Contrary to most organic-inorganic hybrid material, where the organic moieties act as barriers and the inorganic part play the role of quantum well, both organic and inorganic parts in 4BPP[PbBr<sub>3</sub>] are optically active, giving rise to a strong and large emission band covering a wide range of the visible spectrum that can be seen even with the naked eye at room temperature. The photoluminescence spectrum is composed of three bands located at 490 nm (P1), 550 nm (P2) and 600 nm (P3). The first and the second bands are attributed respectivelyto <span><math><mrow><mi>π</mi><mo>−</mo><msup><mi>π</mi><mo>∗</mo></msup></mrow></math></span> and intra-molecular charge transfer transition within the 4BPP organic cation whereas the third band is related to the inorganic Wannier exciton confined in lead bromide PbBr<sub>3</sub> chains. This result was supported by density functional theory calculation. Moreover, the temperature dependence of the PL emission for each transition reveals a different behaviour. In fact, a negative thermal quenching (NTQ) is observed for P1 evolution at low temperature. This NTQ emission is interpreted in terms of transitions between excitonic states involving an exciton-phonon interaction. The P2 observed emission behavior is explained by a charge carrier transfer mechanism between two quantum dots population and the P3 temperature quenching was explained by an increased level of non radiative recombination caused by the phonon vibration (80 cm<sup>−1</sup>) which corresponds well to Pb-Br stretching vibration observed in Raman spectra.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121748"},"PeriodicalIF":3.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multi-phonon-assisted energy relaxation is demonstrated as an effect improving properties of laser media. For the first time, luminescence properties enhancement of germanosilicate bismuth-doped optical active fiber with boron is suggested. Lifetime of luminescence, quantum yield and branching ratio of bismuth active center associated with Si atom (BAC-Si) in Bi-doped germanosilicate fibers were investigated from perspective of their perfection by addition of different boron molar fraction in a fiber core. The most appropriate molar fraction of boron content for optimization of laser characteristics of a germanosilicate bismuth-doped active fiber was evaluated. Einstein coefficients and multi-phonon decay rates of electron transitions in BAC-Si were derived for co-doped with various concentration of boron and bismuth germanosilicate fibers.
{"title":"Phonon-assisted energy relaxation between laser levels of Bi active center associated with Si atom","authors":"A.V. Elopov , K.E. Riumkin , D.S. Serenkov , M.V. Yashkov , A.N. Abramov , A.S. Lobanov , D.F. Burmistrov , S.V. Firstov , M.A. Melkumov","doi":"10.1016/j.jlumin.2026.121744","DOIUrl":"10.1016/j.jlumin.2026.121744","url":null,"abstract":"<div><div>Multi-phonon-assisted energy relaxation is demonstrated as an effect improving properties of laser media. For the first time, luminescence properties enhancement of germanosilicate bismuth-doped optical active fiber with boron is suggested. Lifetime of luminescence, quantum yield and branching ratio of bismuth active center associated with Si atom (BAC-Si) in Bi-doped germanosilicate fibers were investigated from perspective of their perfection by addition of different boron molar fraction in a fiber core. The most appropriate molar fraction of boron content for optimization of laser characteristics of a germanosilicate bismuth-doped active fiber was evaluated. Einstein coefficients and multi-phonon decay rates of electron transitions in BAC-Si were derived for co-doped with various concentration of boron and bismuth germanosilicate fibers.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121744"},"PeriodicalIF":3.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.jlumin.2026.121749
Shuba Paul , Riya Ghanti , Arnab Chakrabarty , Chandan Das , Siddik Sarkar , Sanchita Goswami
The Schiff base probe, 2-Benzothiazol-2-yl-6-[(1-benzyl-piperidin-4-ylimino)-methyl]-4-methylphenol (HBTAP) was constructed by reacting 3-benzothiazolyl-5- methylsalicylaldehyde and 4-amino-1-benzylpiperidine in methanol medium. The resultant probe is characterized by various spectroscopic techniques such as 1H & 13C NMR, ESI-MS, IR and SC-XRD. The fluorescence intensity of the HBTAP solution increases significantly in the presence of only aluminium ion at λmax = 545 nm among other metal ions. Jobs plot and ESI-MS spectrum support a 2:1 binding ratio with Al3+ in ACN-HEPES (8:2, v/v pH = 7.2). The value of limit of detection and binding constant for Al3+ with HBTAP were found to be 66 nM and 8.82 × 103 M−2 respectively. The pronounced increase of yellowish green fluorescence can be referred to as Chelation-enhanced fluorescence (CHEF), established by fluorescence time resolved measurement. Solid state fluorescence study reveals that ESIPT occurs at imine nitrogen side of 4-amino-1-benzylpiperidine part. Ground state optimization and energy calculation of HOMO-LUMO is done by DFT study to confirm the binding mechanism. Additionally, HBTAP can be used successfully to monitor the sensing ability of the probe HBTAP towards Al3+ in MDAMB-231 human cancer cell line.
{"title":"Restriction of photoinduced proton transfer by complexation in dual channel ESIPT active molecule: Fluorimetric Al3+ sensor and live cell imaging","authors":"Shuba Paul , Riya Ghanti , Arnab Chakrabarty , Chandan Das , Siddik Sarkar , Sanchita Goswami","doi":"10.1016/j.jlumin.2026.121749","DOIUrl":"10.1016/j.jlumin.2026.121749","url":null,"abstract":"<div><div>The Schiff base probe, 2-Benzothiazol-2-yl-6-[(1-benzyl-piperidin-4-ylimino)-methyl]-4-methylphenol (<strong>HBTAP</strong>) was constructed by reacting 3-benzothiazolyl-5- methylsalicylaldehyde and 4-amino-1-benzylpiperidine in methanol medium. The resultant probe is characterized by various spectroscopic techniques such as <sup>1</sup>H & <sup>13</sup>C NMR, ESI-MS, IR and SC-XRD. The fluorescence intensity of the <strong>HBTAP</strong> solution increases significantly in the presence of only aluminium ion at <em>λ</em><sub>max</sub> = 545 nm among other metal ions. Jobs plot and ESI-MS spectrum support a 2:1 binding ratio with Al<sup>3+</sup> in ACN-HEPES (8:2, v/v pH = 7.2). The value of limit of detection and binding constant for Al<sup>3+</sup> with <strong>HBTAP</strong> were found to be 66 nM and 8.82 × 10<sup>3</sup> M<sup>−2</sup> respectively. The pronounced increase of yellowish green fluorescence can be referred to as Chelation-enhanced fluorescence (CHEF), established by fluorescence time resolved measurement. Solid state fluorescence study reveals that ESIPT occurs at imine nitrogen side of 4-amino-1-benzylpiperidine part. Ground state optimization and energy calculation of HOMO-LUMO is done by DFT study to confirm the binding mechanism. Additionally, <strong>HBTAP</strong> can be used successfully to monitor the sensing ability of the probe <strong>HBTAP</strong> towards Al<sup>3+</sup> in MDAMB-231 human cancer cell line.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121749"},"PeriodicalIF":3.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.jlumin.2026.121747
Tomasz Uchacz , Paweł Szlachcic , Marcin Andrzejak , Joanna Zams , Piotr Wieczorek , Przemysław Kolek , Katarzyna Stadnicka , Andrzej Danel , Arkadiusz Gut
The design of highly fluorescent chromophores has gained notable interest in recent years. In this work, we synthesized two new dyes based on the 1H-pyrazolo[3,4-b]quinoline scaffold, each bearing a sterically twisted phenyl group at the 1-position of the pyrazole ring. By varying the number of methyl substituents on the phenyl ring (1-(2-methylphenyl) and 1-(2,6-dimethylphenyl)), we were able to tune the torsional angle between the phenyl group and the heterocyclic core. This structural control enabled modulation of key photophysical properties, including fluorescence quantum yield, fluorescence lifetime, emission color, and solvatochromism. The reference compound lacking steric hindrance (1-phenyl-pyrazoloquinoline) displayed polarity-dependent blue-green fluorescence, long fluorescence lifetimes (up to 31 ns), and a large excited-state dipole moment (11.4 D). Increasing steric congestion forced the phenyl ring toward a nearly perpendicular orientation (DFT-predicted torsion ∼80°), reducing electronic coupling with the pyrazole core. This electronic decoupling resulted in highly efficient fluorescence, with quantum yields reaching 100 % and lifetimes of ∼14 ns. Consequently, the emission in polar solvents could be systematically tuned from blue-green to deep blue depending on the number of methyl substituents. The dyes exhibited excellent photostability, with only 1.5 % degradation after 6 h of irradiation at 350 nm, as well as high thermal stability and no tendency to aggregate. Furthermore, the investigated compounds maintained near-unity fluorescence quantum yields even when incorporated into a polymer matrix. These features suggest strong potential for optical applications, particularly as fluorescence quantum yield standards. The experimental observations were supported by quantum-chemical calculations, X-ray crystallography, and cyclic voltammetry measurements.
{"title":"Twist-controlled electronic conjugation in pyrazoloquinoline dyes: Photostable blue emitters with near-unity fluorescence quantum yields","authors":"Tomasz Uchacz , Paweł Szlachcic , Marcin Andrzejak , Joanna Zams , Piotr Wieczorek , Przemysław Kolek , Katarzyna Stadnicka , Andrzej Danel , Arkadiusz Gut","doi":"10.1016/j.jlumin.2026.121747","DOIUrl":"10.1016/j.jlumin.2026.121747","url":null,"abstract":"<div><div>The design of highly fluorescent chromophores has gained notable interest in recent years. In this work, we synthesized two new dyes based on the 1<em>H</em>-pyrazolo[3,4-<em>b</em>]quinoline scaffold, each bearing a sterically twisted phenyl group at the 1-position of the pyrazole ring. By varying the number of methyl substituents on the phenyl ring (1-(2-methylphenyl) and 1-(2,6-dimethylphenyl)), we were able to tune the torsional angle between the phenyl group and the heterocyclic core. This structural control enabled modulation of key photophysical properties, including fluorescence quantum yield, fluorescence lifetime, emission color, and solvatochromism. The reference compound lacking steric hindrance (1-phenyl-pyrazoloquinoline) displayed polarity-dependent blue-green fluorescence, long fluorescence lifetimes (up to 31 ns), and a large excited-state dipole moment (11.4 D). Increasing steric congestion forced the phenyl ring toward a nearly perpendicular orientation (DFT-predicted torsion ∼80°), reducing electronic coupling with the pyrazole core. This electronic decoupling resulted in highly efficient fluorescence, with quantum yields reaching 100 % and lifetimes of ∼14 ns. Consequently, the emission in polar solvents could be systematically tuned from blue-green to deep blue depending on the number of methyl substituents. The dyes exhibited excellent photostability, with only 1.5 % degradation after 6 h of irradiation at 350 nm, as well as high thermal stability and no tendency to aggregate. Furthermore, the investigated compounds maintained near-unity fluorescence quantum yields even when incorporated into a polymer matrix. These features suggest strong potential for optical applications, particularly as fluorescence quantum yield standards. The experimental observations were supported by quantum-chemical calculations, X-ray crystallography, and cyclic voltammetry measurements.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"292 ","pages":"Article 121747"},"PeriodicalIF":3.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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