Pub Date : 2024-10-16DOI: 10.1016/j.jlumin.2024.120944
Sanghun Byeon, Mohammad M. Afandi, Busic Kang, Jongsu Kim
The continuous utilization of ultraviolet (UV) light sources within both academic and industrial contexts necessitates the imperative advancement of alternative UV sources to replace hazardous mercury lamps. Herein, we proposed a mercury-free narrowband UVB (NB-UVB)-emitting device from Y2O3:Gd3+ nanofilm on a tubular quartz substrate. The nanofilm is fabricated utilizing the spin-coating sol-gel precursor technique and is subsequently synthesized via a high-annealing temperature solid-state reaction. This synthesis resulted in the formation of a single-phase cubical structure of Y2O3 characterized by a crack-free morphology. The NB-UVB radiative output with a peak at 315 nm is generated through vacuum UV-induced photoluminescence originating from the emission of Xe excimer, which subsequently excites the Gd3+ luminescent centers incorporated within the Y2O3 host matrix. Moreover, in a high-voltage bipolar power system operating at 19 kV and 19 kHz, the device exhibited an NB-UVB radiance output of 1.34 mW, accompanied by a power efficiency of 0.02 %, whilst preserving exceptional temporal performance. Thus, this investigation introduces an innovative perspective on a mercury-free NB-UVB-emitting device, thereby promoting further exploration into the application of UV radiation sources derived from excimer lamp technology.
{"title":"Narrowband-UVB-emitting gadolinium-doped yttrium oxide nanofilm on xenon excimer lamp for phototherapy","authors":"Sanghun Byeon, Mohammad M. Afandi, Busic Kang, Jongsu Kim","doi":"10.1016/j.jlumin.2024.120944","DOIUrl":"10.1016/j.jlumin.2024.120944","url":null,"abstract":"<div><div>The continuous utilization of ultraviolet (UV) light sources within both academic and industrial contexts necessitates the imperative advancement of alternative UV sources to replace hazardous mercury lamps. Herein, we proposed a mercury-free narrowband UVB (NB-UVB)-emitting device from Y<sub>2</sub>O<sub>3</sub>:Gd<sup>3+</sup> nanofilm on a tubular quartz substrate. The nanofilm is fabricated utilizing the spin-coating sol-gel precursor technique and is subsequently synthesized via a high-annealing temperature solid-state reaction. This synthesis resulted in the formation of a single-phase cubical structure of Y<sub>2</sub>O<sub>3</sub> characterized by a crack-free morphology. The NB-UVB radiative output with a peak at 315 nm is generated through vacuum UV-induced photoluminescence originating from the emission of Xe excimer, which subsequently excites the Gd<sup>3+</sup> luminescent centers incorporated within the Y<sub>2</sub>O<sub>3</sub> host matrix. Moreover, in a high-voltage bipolar power system operating at 19 kV and 19 kHz, the device exhibited an NB-UVB radiance output of 1.34 mW, accompanied by a power efficiency of 0.02 %, whilst preserving exceptional temporal performance. Thus, this investigation introduces an innovative perspective on a mercury-free NB-UVB-emitting device, thereby promoting further exploration into the application of UV radiation sources derived from excimer lamp technology.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120944"},"PeriodicalIF":3.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540276","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}
In the context of the rapid advances in electronic information technology, the advancement of novel high-efficiency narrow-band blue phosphors represents a pivotal step in the advancement of high-quality liquid crystal displays (LCDs), as well as the development of white light-emitting diodes (WLEDs) with a reduced correlated color temperature (CCT). In this study, based on the sensitivity of Eu2+ emission to local environment, the alkaline earth aluminate material CaAl12O19 with high structural symmetry was selected as the matrix, and the symmetry of crystal structure was improved by replacing Ca2+ with Sr2+, the narrow-band emission of the phosphor is realized. The Sr0.9Ca0.09Al12O19: 0.01Eu2+ (SCAO: Eu2+) phosphor exhibited narrow-band emission with the full width at half maximum (FWHM) of 45.76 nm, and the colour purity of up to 95.46 %. Moreover, the internal quantum efficiency (IQE) of SCAO: Eu2+ has been demonstrated to reach 81.70 %. In addition, SCAO: Eu2+ phosphor, (Ba, Sr)2SiO4: Eu2+ phosphor, CaAlSiN3: Eu2+ phosphor, and 275 nm UVLED chips were combined to prepare white LED devices exhibiting a low color temperature (3733 K). The three-band LEDs of SCAO: Eu2+, β-Sialon: Eu2+ and K2SiF6: Mn4+ exhibited a colour gamut covering 84.75 % of the National Television Standards Committee (NTSC) standard. This indicates that the phosphor possesses the characteristics of a highly effective narrow-band blue-light-emitting substance with considerable potential for utilization in lighting and backlighting displays.
{"title":"High color purity aluminate phosphor SryCa1-x-yAl12O19: xEu2+ for lighting and backlight display applications","authors":"Zhaofeng Tian, Yangai Liu, Ci'an Xie, Juyu Yang, Yukun Liu, Chenguang Yang, Ruiyu Mi, Lefu Mei","doi":"10.1016/j.jlumin.2024.120941","DOIUrl":"10.1016/j.jlumin.2024.120941","url":null,"abstract":"<div><div>In the context of the rapid advances in electronic information technology, the advancement of novel high-efficiency narrow-band blue phosphors represents a pivotal step in the advancement of high-quality liquid crystal displays (LCDs), as well as the development of white light-emitting diodes (WLEDs) with a reduced correlated color temperature (CCT). In this study, based on the sensitivity of Eu<sup>2+</sup> emission to local environment, the alkaline earth aluminate material CaAl<sub>12</sub>O<sub>19</sub> with high structural symmetry was selected as the matrix, and the symmetry of crystal structure was improved by replacing Ca<sup>2+</sup> with Sr<sup>2+</sup>, the narrow-band emission of the phosphor is realized. The Sr<sub>0.9</sub>Ca<sub>0.09</sub>Al<sub>12</sub>O<sub>19</sub>: 0.01Eu<sup>2+</sup> (SCAO: Eu<sup>2+</sup>) phosphor exhibited narrow-band emission with the full width at half maximum (FWHM) of 45.76 nm, and the colour purity of up to 95.46 %. Moreover, the internal quantum efficiency (IQE) of SCAO: Eu<sup>2+</sup> has been demonstrated to reach 81.70 %. In addition, SCAO: Eu<sup>2+</sup> phosphor, (Ba, Sr)<sub>2</sub>SiO<sub>4</sub>: Eu<sup>2+</sup> phosphor, CaAlSiN<sub>3</sub>: Eu<sup>2+</sup> phosphor, and 275 nm UVLED chips were combined to prepare white LED devices exhibiting a low color temperature (3733 K). The three-band LEDs of SCAO: Eu<sup>2+</sup>, β-Sialon: Eu<sup>2+</sup> and K<sub>2</sub>SiF<sub>6</sub>: Mn<sup>4+</sup> exhibited a colour gamut covering 84.75 % of the National Television Standards Committee (NTSC) standard. This indicates that the phosphor possesses the characteristics of a highly effective narrow-band blue-light-emitting substance with considerable potential for utilization in lighting and backlighting displays.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120941"},"PeriodicalIF":3.3,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433676","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 : 2024-10-12DOI: 10.1016/j.jlumin.2024.120940
Yonggang Yang , Feiyao Geng , Zhinan Jiang , Yang Liu , Tiantian Guan , Chaochao Qin , Chunsheng Zhuang , Yufang Liu
Heavy atom activated organic room-temperature phosphorescence (RTP) has attracted considerable interest due to its high phosphorescence quantum yield and prolonged lifetime. This research provides a detailed analysis of the transient absorption spectroscopy of 1,3-Bis(N-carbazolyl)benzene (mCP) and 9,9'-(5-Bromo-1,3-phenylene)bis(9H-carbazole) (Br-mCP) in toluene solution. In the femtosecond transient absorption (fs-TA) spectroscopy of mCP, the excited state absorption (ESA) signal decreases at 630 nm while the triplet-triplet absorption (TTA) signal increases at 420 nm. Meanwhile, the isosbestic point observed at 455 nm indicates an intersystem crossing (ISC) lifetime of 15.4 ns. Moving on to the nanosecond transient absorption (ns-TA) spectroscopy, the TTA signal reaches its peak at 27.3 ns before decreasing, with the triplet lifetime of mCP measured at 2.8 μs. Br-mCP exhibits a similar dynamic evolution to mCP, but with a quicker ISC process (9.4 ns) and a longer triplet lifetime (3.9 μs). The quicker ISC process in Br-mCP is ascribed to the presence of heavy atom in the molecular structure, leading to an enhanced spin-orbit coupling constant (ξ(S1, T3)Br-mCP = 1.371 cm−1 > ξ(S1, T4)mCP = 0.060 cm−1). The prolonged triplet lifetime of Br-mCP (3.9 μs > 2.8 μs) results from its lower reorganization energy, effectively reducing non-radiative vibrational energy losses within the molecule. This work significantly enhances our understanding of RTP materials incorporating heavy atoms.
{"title":"Ultrafast dynamics of mCP and Br-mCP: Insights from transient absorption spectroscopy","authors":"Yonggang Yang , Feiyao Geng , Zhinan Jiang , Yang Liu , Tiantian Guan , Chaochao Qin , Chunsheng Zhuang , Yufang Liu","doi":"10.1016/j.jlumin.2024.120940","DOIUrl":"10.1016/j.jlumin.2024.120940","url":null,"abstract":"<div><div>Heavy atom activated organic room-temperature phosphorescence (RTP) has attracted considerable interest due to its high phosphorescence quantum yield and prolonged lifetime. This research provides a detailed analysis of the transient absorption spectroscopy of 1,3-Bis(N-carbazolyl)benzene (mCP) and 9,9'-(5-Bromo-1,3-phenylene)bis(9H-carbazole) (Br-mCP) in toluene solution. In the femtosecond transient absorption (fs-TA) spectroscopy of mCP, the excited state absorption (ESA) signal decreases at 630 nm while the triplet-triplet absorption (TTA) signal increases at 420 nm. Meanwhile, the isosbestic point observed at 455 nm indicates an intersystem crossing (ISC) lifetime of 15.4 ns. Moving on to the nanosecond transient absorption (ns-TA) spectroscopy, the TTA signal reaches its peak at 27.3 ns before decreasing, with the triplet lifetime of mCP measured at 2.8 μs. Br-mCP exhibits a similar dynamic evolution to mCP, but with a quicker ISC process (9.4 ns) and a longer triplet lifetime (3.9 μs). The quicker ISC process in Br-mCP is ascribed to the presence of heavy atom in the molecular structure, leading to an enhanced spin-orbit coupling constant (ξ(S<sub>1</sub>, T<sub>3</sub>)<sub>Br-mCP</sub> = 1.371 cm<sup>−1</sup> > ξ(S<sub>1</sub>, T<sub>4</sub>)<sub>mCP</sub> = 0.060 cm<sup>−1</sup>). The prolonged triplet lifetime of Br-mCP (3.9 μs > 2.8 μs) results from its lower reorganization energy, effectively reducing non-radiative vibrational energy losses within the molecule. This work significantly enhances our understanding of RTP materials incorporating heavy atoms.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120940"},"PeriodicalIF":3.3,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446509","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 : 2024-10-11DOI: 10.1016/j.jlumin.2024.120936
A. Idini , R. Argazzi , F. Frau , M. Fantauzzi , C. Angeli
Gem quality garnet var. tsavorite from Tanzania is investigated by means of SEM-EDS, XPS and fluorescence spectroscopy to decipher its luminescence spectrum. The EDS analysis confirms that the main constituents of the tsavorite samples from Tanzania are those of grossularia (i.e. Ca, Al, Si, O), with V, Mn, Cr, Ti and Mg as minor but characteristic elements (particularly V, Mn and Cr) of the tsavorite variety. The XPS analysis shows that the oxidation state of Mn is +2 and that of V is +3. The luminescence of tsavorite in the yellow region (591 nm) is originated by Mn2+ in dodecahedral coordination (D2 point symmetry) while the luminescence in the red region (690–750 nm) is originated by Cr3+ in octahedral coordination (Oh point symmetry) in a strong crystal field. Contrary to what is often reported in the literature, this study demonstrates that V2+ (or other 3d transition metal ions as well) is not responsible for the red emissions of tsavorite.
{"title":"Unravelling the luminescence spectrum of garnet grossular var. tsavorite: The role of chromium (III), manganese (II) and misattribution of vanadium (II)","authors":"A. Idini , R. Argazzi , F. Frau , M. Fantauzzi , C. Angeli","doi":"10.1016/j.jlumin.2024.120936","DOIUrl":"10.1016/j.jlumin.2024.120936","url":null,"abstract":"<div><div>Gem quality garnet var. tsavorite from Tanzania is investigated by means of SEM-EDS, XPS and fluorescence spectroscopy to decipher its luminescence spectrum. The EDS analysis confirms that the main constituents of the tsavorite samples from Tanzania are those of grossularia (i.e. Ca, Al, Si, O), with V, Mn, Cr, Ti and Mg as minor but characteristic elements (particularly V, Mn and Cr) of the tsavorite variety. The XPS analysis shows that the oxidation state of Mn is +2 and that of V is +3. The luminescence of tsavorite in the yellow region (591 nm) is originated by Mn<sup>2+</sup> in dodecahedral coordination (D<sub>2</sub> point symmetry) while the luminescence in the red region (690–750 nm) is originated by Cr<sup>3+</sup> in octahedral coordination (O<sub>h</sub> point symmetry) in a strong crystal field. Contrary to what is often reported in the literature, this study demonstrates that V<sup>2+</sup> (or other 3d transition metal ions as well) is not responsible for the red emissions of tsavorite.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120936"},"PeriodicalIF":3.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The fabrication of 0.1, 0.5, 1.0, and 5.0 % Nd:La2Be2O5 single crystals was carried out by the floating zone method, and photoluminescence (PL) and scintillation properties were measured. The PL spectra showed some emission lines which was derived from the 4f-4f transitions of Nd3+ ions. The scintillation spectra showed a broad emission band originating from some lattice defect and the emission lines due to the 4f–4f transitions of Nd3+ ions. The afterglow levels of Nd:La2Be2O5 were 192.3 (0.1 % Nd), 205.9 (0.5 % Nd), 228.2 (1.0 % Nd), and 315.4 (5.0 % Nd) ppm. The 1.0 % Nd:La2Be2O5 showed the highest intensity in the dose-rate response functions among the samples, and a lower detection limit was 0.003 Gy/h.
{"title":"Ultraviolet–near infrared luminescence characteristics of Nd:La2Be2O5 single crystals for near-infrared emitting scintillators","authors":"Kensei Ichiba, Takumi Kato, Daisuke Nakauchi, Noriaki Kawaguchi, Takayuki Yanagida","doi":"10.1016/j.jlumin.2024.120938","DOIUrl":"10.1016/j.jlumin.2024.120938","url":null,"abstract":"<div><div>The fabrication of 0.1, 0.5, 1.0, and 5.0 % Nd:La<sub>2</sub>Be<sub>2</sub>O<sub>5</sub> single crystals was carried out by the floating zone method, and photoluminescence (PL) and scintillation properties were measured. The PL spectra showed some emission lines which was derived from the 4f-4f transitions of Nd<sup>3+</sup> ions. The scintillation spectra showed a broad emission band originating from some lattice defect and the emission lines due to the 4f–4f transitions of Nd<sup>3+</sup> ions. The afterglow levels of Nd:La<sub>2</sub>Be<sub>2</sub>O<sub>5</sub> were 192.3 (0.1 % Nd), 205.9 (0.5 % Nd), 228.2 (1.0 % Nd), and 315.4 (5.0 % Nd) ppm. The 1.0 % Nd:La<sub>2</sub>Be<sub>2</sub>O<sub>5</sub> showed the highest intensity in the dose-rate response functions among the samples, and a lower detection limit was 0.003 Gy/h.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120938"},"PeriodicalIF":3.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433674","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 : 2024-10-11DOI: 10.1016/j.jlumin.2024.120937
Yingjie Mao , Zhichao Zhang , Guojun Zhou , Chen Fang , Yihan Liu , Denghui Xu , Jia Zhao , Aicong Geng , Jun Zhou
Zero-dimensional (0D) Mn(II)-based hybrids with the typical d–d transitions have been rapidly developed benefitting from the environmental friendliness, blue light excitation and the high thermal stability. Herein, we first designed two novel green-emitting 0D Mn(II)-based hybrids (C16H28N)2MnCl4 and (C21H46N)2MnCl4, where the organic cations cocrystallize with four-coordinated [MnCl4]2- tetrahedrons. Upon blue-light excitation, these two crystals exhibited narrow-band green emission with distinct emission intensity and FWHM as well as thermal quenching behavior, which is analyzed by the influence of the crystal structure of different organic cations on the luminescence performance. Furthermore, multiple emission color can be observed from green to orange-red in (C16H28N)2MnCl4:Sb3+ by regulating the [SbCl5]2-/[MnCl4]2- molar ratio or excitation wavelength. Our study not only enriches the influence of organic cations on crystal structure and luminescence performance, but also provides a new direction towards realizing the multi-color emission by Sb3+ ions doping strategy.
{"title":"Efficient manipulation of photoluminescence by organic cations and Sb doping in hybrid manganese chlorides","authors":"Yingjie Mao , Zhichao Zhang , Guojun Zhou , Chen Fang , Yihan Liu , Denghui Xu , Jia Zhao , Aicong Geng , Jun Zhou","doi":"10.1016/j.jlumin.2024.120937","DOIUrl":"10.1016/j.jlumin.2024.120937","url":null,"abstract":"<div><div>Zero-dimensional (0D) Mn(II)-based hybrids with the typical d–d transitions have been rapidly developed benefitting from the environmental friendliness, blue light excitation and the high thermal stability. Herein, we first designed two novel green-emitting 0D Mn(II)-based hybrids (C<sub>16</sub>H<sub>28</sub>N)<sub>2</sub>MnCl<sub>4</sub> and (C<sub>21</sub>H<sub>46</sub>N)<sub>2</sub>MnCl<sub>4</sub>, where the organic cations cocrystallize with four-coordinated [MnCl<sub>4</sub>]<sup>2-</sup> tetrahedrons. Upon blue-light excitation, these two crystals exhibited narrow-band green emission with distinct emission intensity and FWHM as well as thermal quenching behavior, which is analyzed by the influence of the crystal structure of different organic cations on the luminescence performance. Furthermore, multiple emission color can be observed from green to orange-red in (C<sub>16</sub>H<sub>28</sub>N)<sub>2</sub>MnCl<sub>4</sub>:Sb<sup>3+</sup> by regulating the [SbCl<sub>5</sub>]<sup>2-</sup>/[MnCl<sub>4</sub>]<sup>2-</sup> molar ratio or excitation wavelength. Our study not only enriches the influence of organic cations on crystal structure and luminescence performance, but also provides a new direction towards realizing the multi-color emission by Sb<sup>3+</sup> ions doping strategy.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120937"},"PeriodicalIF":3.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540267","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 : 2024-10-11DOI: 10.1016/j.jlumin.2024.120939
Rahul Kumar , Yurii Maidaniuk , Fernando Maia de Oliveira , Yuriy I. Mazur , Gregory J. Salamo
Temperature-dependent photoluminescence (TDPL) and time-resolved photoluminescence (TRPL) of ultrathin InAs quantum wells (QWs) in GaAs matrix have been investigated to understand the optical properties of carriers. Samples containing different thicknesses of InAs (0.5, 0.75, 1, 1.2, 1.4 monolayers) have been used for this study. The PL peak position of InAs with temperature does not follow the Varshni model at low temperatures. The activation energy (EA) of these QWs has been calculated from TDPL. As expected, the thinnest QW sample (0.5 monolayer) results in the smallest EA of 23 meV, whereas the thickest QW sample (1.4 monolayer) results in the highest EA of 79 meV. Carrier lifetime has been calculated from TRPL measurement for varying temperatures. At 10 K, the carrier lifetime increased almost linearly from 250 to 800 ps with the InAs QW thickness. Thicker InAs QW results in a longer carrier lifetime, which has been explained by the carrier escape model. Higher temperatures resulted in a decrease in carrier lifetime, which suggests carrier escape is dominating the temporal decay behavior.
{"title":"Temperature dependent optical properties of ultrathin InAs quantum well","authors":"Rahul Kumar , Yurii Maidaniuk , Fernando Maia de Oliveira , Yuriy I. Mazur , Gregory J. Salamo","doi":"10.1016/j.jlumin.2024.120939","DOIUrl":"10.1016/j.jlumin.2024.120939","url":null,"abstract":"<div><div>Temperature-dependent photoluminescence (TDPL) and time-resolved photoluminescence (TRPL) of ultrathin InAs quantum wells (QWs) in GaAs matrix have been investigated to understand the optical properties of carriers. Samples containing different thicknesses of InAs (0.5, 0.75, 1, 1.2, 1.4 monolayers) have been used for this study. The PL peak position of InAs with temperature does not follow the Varshni model at low temperatures. The activation energy (<em>E</em><sub><em>A</em></sub>) of these QWs has been calculated from TDPL. As expected, the thinnest QW sample (0.5 monolayer) results in the smallest <em>E</em><sub><em>A</em></sub> of 23 meV, whereas the thickest QW sample (1.4 monolayer) results in the highest E<sub>A</sub> of 79 meV. Carrier lifetime has been calculated from TRPL measurement for varying temperatures. At 10 K, the carrier lifetime increased almost linearly from 250 to 800 ps with the InAs QW thickness. Thicker InAs QW results in a longer carrier lifetime, which has been explained by the carrier escape model. Higher temperatures resulted in a decrease in carrier lifetime, which suggests carrier escape is dominating the temporal decay behavior.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120939"},"PeriodicalIF":3.3,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433675","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 : 2024-10-10DOI: 10.1016/j.jlumin.2024.120935
Haoquan Wang , Qi Yang , Yan Zhang , Bo Peng , Feng Wu , Zewei Quan
Developing a SERS nanotag with high signal intensity, excellent signal stability, and biocompatibility is of significant importance in the fields of food safety, drug testing, and virus detection. In this work, silica-encapsulated, indocyanine green (ICG)-modified Au octahedral core-small Au spherical nanoparticles (NPs) satellite nanostructures (Au/Au@ICG@SiO2) are uniformly synthesized as surface-enhanced Raman scattering (SERS) tags, which provide abundant “hot spots” and also increase the stability of Raman reporter molecule ICG to greatly facilitate subsequent functionalization and detection. Both experimental and numerical results demonstrate that this Au/Au@ICG nanostructure achieve a detection limit of 10⁻⁷ M for ICG in aqueous solution ascribed to the increased number of hot spots compared with Au octahedral NPs. As-prepared Au/Au@ICG@SiO2 SERS nanotags are further integrated with a lateral flow immunoassay (LFIA) for the detection of the SARS-CoV-2 nucleocapsid protein. Compared to the traditional bio-recognition method on LFIA strips with the detection limit of 8 pg/mL, the detection capability for the SARS-CoV-2 nucleocapsid protein is improved approximately 16 times (500 fg/mL) based on this novel SERS tag and custom-built adaptive Raman mapping spectrometer. This Au/Au@ICG@SiO2 SERS tag is expected to play a significant role in early detection, prevention, and control of similar infectious viruses in the future.
{"title":"Synthesis of novel silica-encapsulated core-satellite nanotags for enhanced SERS detection","authors":"Haoquan Wang , Qi Yang , Yan Zhang , Bo Peng , Feng Wu , Zewei Quan","doi":"10.1016/j.jlumin.2024.120935","DOIUrl":"10.1016/j.jlumin.2024.120935","url":null,"abstract":"<div><div>Developing a SERS nanotag with high signal intensity, excellent signal stability, and biocompatibility is of significant importance in the fields of food safety, drug testing, and virus detection. In this work, silica-encapsulated, indocyanine green (ICG)-modified Au octahedral core-small Au spherical nanoparticles (NPs) satellite nanostructures (Au/Au@ICG@SiO<sub>2</sub>) are uniformly synthesized as surface-enhanced Raman scattering (SERS) tags, which provide abundant “hot spots” and also increase the stability of Raman reporter molecule ICG to greatly facilitate subsequent functionalization and detection. Both experimental and numerical results demonstrate that this Au/Au@ICG nanostructure achieve a detection limit of 10⁻⁷ M for ICG in aqueous solution ascribed to the increased number of hot spots compared with Au octahedral NPs. As-prepared Au/Au@ICG@SiO<sub>2</sub> SERS nanotags are further integrated with a lateral flow immunoassay (LFIA) for the detection of the SARS-CoV-2 nucleocapsid protein. Compared to the traditional bio-recognition method on LFIA strips with the detection limit of 8 pg/mL, the detection capability for the SARS-CoV-2 nucleocapsid protein is improved approximately 16 times (500 fg/mL) based on this novel SERS tag and custom-built adaptive Raman mapping spectrometer. This Au/Au@ICG@SiO<sub>2</sub> SERS tag is expected to play a significant role in early detection, prevention, and control of similar infectious viruses in the future.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120935"},"PeriodicalIF":3.3,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423421","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 : 2024-10-10DOI: 10.1016/j.jlumin.2024.120932
Rafael F. Salgueiro , Fernando E. Maturi , Victor M.P. da Silva , Danilo Manzani , Carlos D.S. Brites
The rapid miniaturization of electronic devices has pushed the limits of conventional silicon-based technologies, creating a pressing need for novel approaches to sustain the exponential growth of computing power. This study explores the innovative application of Ln3+-doped glasses in developing molecular logic systems as a potential solution. Exploiting Eu3+ and Dy3+, we investigated the luminescence properties under various physical stimuli such as excitation wavelength and temperature. Our findings reveal the capability to construct logic elements of varying complexity, from simple AND and OR gates to advanced FULL-ADDER and FULL-SUBTRACTOR circuits. This work represents the first instance of using Ln3+ exclusively for molecular logic via physical stimuli. The robust and stable optical properties of the doped glasses enable their integration into conventional electronic and photonic devices, potentially revolutionizing the landscape of molecular logic and computing. This research not only enhances the understanding of light-matter interactions in Ln3+-doped systems but also opens new pathways for the development of miniaturized, high-performance innovative computational devices.
电子设备的快速微型化已经突破了传统硅基技术的极限，因此迫切需要新的方法来维持计算能力的指数级增长。本研究探索了掺 Ln3+ 玻璃在开发分子逻辑系统中的创新应用，以此作为一种潜在的解决方案。我们利用 Eu3+ 和 Dy3+ 研究了激发波长和温度等各种物理刺激下的发光特性。我们的研究结果揭示了构建不同复杂程度逻辑元件的能力，从简单的 AND 和 OR 门到先进的全加法器和全减法器电路。这项工作代表了通过物理刺激将 Ln3+ 完全用于分子逻辑的首个实例。掺杂玻璃坚固稳定的光学特性使其能够集成到传统的电子和光子设备中，从而有可能彻底改变分子逻辑和计算的面貌。这项研究不仅加深了人们对掺杂 Ln3+ 系统中光与物质相互作用的理解，还为开发小型化、高性能的创新计算设备开辟了新途径。
{"title":"Ln3+-doped glasses: Advancing molecular logic for integration into photonic and electronic devices","authors":"Rafael F. Salgueiro , Fernando E. Maturi , Victor M.P. da Silva , Danilo Manzani , Carlos D.S. Brites","doi":"10.1016/j.jlumin.2024.120932","DOIUrl":"10.1016/j.jlumin.2024.120932","url":null,"abstract":"<div><div>The rapid miniaturization of electronic devices has pushed the limits of conventional silicon-based technologies, creating a pressing need for novel approaches to sustain the exponential growth of computing power. This study explores the innovative application of Ln<sup>3+</sup>-doped glasses in developing molecular logic systems as a potential solution. Exploiting Eu<sup>3+</sup> and Dy<sup>3+</sup>, we investigated the luminescence properties under various physical stimuli such as excitation wavelength and temperature. Our findings reveal the capability to construct logic elements of varying complexity, from simple AND and OR gates to advanced FULL-ADDER and FULL-SUBTRACTOR circuits. This work represents the first instance of using Ln<sup>3+</sup> exclusively for molecular logic via physical stimuli. The robust and stable optical properties of the doped glasses enable their integration into conventional electronic and photonic devices, potentially revolutionizing the landscape of molecular logic and computing. This research not only enhances the understanding of light-matter interactions in Ln<sup>3+</sup>-doped systems but also opens new pathways for the development of miniaturized, high-performance innovative computational devices.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120932"},"PeriodicalIF":3.3,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433673","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 : 2024-10-05DOI: 10.1016/j.jlumin.2024.120934
Tim Pier, Franziska Schröder, Jan Kappelhoff, Julia Hopster, Thomas Jüstel
In this work the optical properties of two distinct, praseodymium activated, UV-C emitting pyrophosphate polymorphs are presented. The materials were obtained as single-phase samples using a facile solid state method with annealing at target phase-dependent temperatures. The activator concentration dependent luminescence quenching was investigated revealing significant differences between the [Xe]4f2 → [Xe]4f2 and the [Xe]4f15d1 → [Xe]4f2 transitions. The highest emission intensities were observed at Pr3+ concentration of 0.5 and 2.0 % for the [Xe]4f2 → [Xe]4f2 line and the [Xe]4f15d1 → [Xe]4f2 band emission, respectively. Furthermore, temperature dependent fluorescence spectroscopy and VUV spectroscopy were employed to investigate the thermal quenching behaviour as well as the excitation and emission properties in the deep UV range. Fitting of the temperature dependent emission integrals showed thermal quenching temperatures exceeding 700 K. It was revealed that the samples show two types of emission that can be traced back to the inter- and intraconfigurational transition of trivalent praseodymium. Praseodymium emission bands around 235 and 265 nm correspond to the various [Xe]4f15d1 → [Xe]4f2 interconfigurational transitions. Meanwhile, narrow emission lines throughout the visible and NIR range are caused by the [Xe]4f2 → [Xe]4f2 intraconfigurational transitions of Pr3+. Qualitative and quantitative comparisons between the emission properties of the two polymorphs revealed significant differences arising from the different coordination environments. α-Ca2P2O7:Pr phosphors exhibited around 60 % of the emission intensities of the β-Ca2P2O7 materials in the red spectral range while a reversed trend was observed for the UV emission caused by [Xe]4f15d1 → [Xe]4f2 transitions.
{"title":"On the photoluminescence of Pr(III) activated Ca2P2O7 polymorphs","authors":"Tim Pier, Franziska Schröder, Jan Kappelhoff, Julia Hopster, Thomas Jüstel","doi":"10.1016/j.jlumin.2024.120934","DOIUrl":"10.1016/j.jlumin.2024.120934","url":null,"abstract":"<div><div>In this work the optical properties of two distinct, praseodymium activated, UV-C emitting pyrophosphate polymorphs are presented. The materials were obtained as single-phase samples using a facile solid state method with annealing at target phase-dependent temperatures. The activator concentration dependent luminescence quenching was investigated revealing significant differences between the <em>[Xe]4f</em><sup><em>2</em></sup> → <em>[Xe]4f</em><sup><em>2</em></sup> and the <em>[Xe]4f</em><sup><em>1</em></sup><em>5d</em><sup><em>1</em></sup> → <em>[Xe]4f</em><sup><em>2</em></sup> transitions. The highest emission intensities were observed at Pr<sup>3+</sup> concentration of 0.5 and 2.0 % for the <em>[Xe]4f</em><sup><em>2</em></sup> → <em>[Xe]4f</em><sup><em>2</em></sup> line and the <em>[Xe]4f</em><sup><em>1</em></sup><em>5d</em><sup><em>1</em></sup> → <em>[Xe]4f</em><sup><em>2</em></sup> band emission, respectively. Furthermore, temperature dependent fluorescence spectroscopy and VUV spectroscopy were employed to investigate the thermal quenching behaviour as well as the excitation and emission properties in the deep UV range. Fitting of the temperature dependent emission integrals showed thermal quenching temperatures exceeding 700 K. It was revealed that the samples show two types of emission that can be traced back to the inter- and intraconfigurational transition of trivalent praseodymium. Praseodymium emission bands around 235 and 265 nm correspond to the various <em>[Xe]4f</em><sup><em>1</em></sup><em>5d</em><sup><em>1</em></sup> → <em>[Xe]4f</em><sup><em>2</em></sup> interconfigurational transitions. Meanwhile, narrow emission lines throughout the visible and NIR range are caused by the <em>[Xe]4f</em><sup><em>2</em></sup> → <em>[Xe]4f</em><sup><em>2</em></sup> intraconfigurational transitions of Pr<sup>3+</sup>. Qualitative and quantitative comparisons between the emission properties of the two polymorphs revealed significant differences arising from the different coordination environments. α-Ca<sub>2</sub>P<sub>2</sub>O<sub>7</sub>:Pr phosphors exhibited around 60 % of the emission intensities of the β-Ca<sub>2</sub>P<sub>2</sub>O<sub>7</sub> materials in the red spectral range while a reversed trend was observed for the UV emission caused by <em>[Xe]4f</em><sup><em>1</em></sup><em>5d</em><sup><em>1</em></sup> → <em>[Xe]4f</em><sup><em>2</em></sup> transitions.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120934"},"PeriodicalIF":3.3,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423449","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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