A pair of novel chiral AIE enantiomers (S-ETMPB and R-ETMPB) with entirely opposite mechanoluminescence activities were demonstrated here. R-ETMPB displayed reversible turn-on mechanofluorochromism with a significant increase in quantum yield (QY), whereas S-ETMPB exhibited reversible turn-off mechanofluorochromism. Notably, the processes of grinding-fumigation and heating can be repeated over multiple cycles, demonstrating good reversibility without signs of fatigue. The reversible physical transformation between the crystalline and amorphous phases has been shown to account for the distinct mechanofluorochromic behaviors. Furthermore, both enantiomers possess the characteristic property of aggregation-induced emission. As the water content increases, the fluorescence quantum yields of S-ETMPB and R-ETMPB can significantly rise from 0.56 % to 0.86 % to maximum values of 18.89 % and 23.61 %, resulting in AIE factors of approximately 33.7 for S-ETMPB and 27.5 for R-ETMPB, respectively.
{"title":"Mechano-responsive fluorescent AIE enantiomers with high contrast properties","authors":"Pan-Pan Hua, Jing-Wen Xu, Jun-Fei Li, Yun-Long Fu, Jun-Wen Wang, Li-Fang Zhang","doi":"10.1016/j.jlumin.2024.120963","DOIUrl":"10.1016/j.jlumin.2024.120963","url":null,"abstract":"<div><div>A pair of novel chiral AIE enantiomers (<strong>S-ETMPB</strong> and <strong>R-ETMPB</strong>) with entirely opposite mechanoluminescence activities were demonstrated here. <strong>R-ETMPB</strong> displayed reversible turn-on mechanofluorochromism with a significant increase in quantum yield (QY), whereas <strong>S-ETMPB</strong> exhibited reversible turn-off mechanofluorochromism. Notably, the processes of grinding-fumigation and heating can be repeated over multiple cycles, demonstrating good reversibility without signs of fatigue. The reversible physical transformation between the crystalline and amorphous phases has been shown to account for the distinct mechanofluorochromic behaviors. Furthermore, both enantiomers possess the characteristic property of aggregation-induced emission. As the water content increases, the fluorescence quantum yields of <strong>S-ETMPB</strong> and <strong>R-ETMPB</strong> can significantly rise from 0.56 % to 0.86 % to maximum values of 18.89 % and 23.61 %, resulting in AIE factors of approximately 33.7 for <strong>S-ETMPB</strong> and 27.5 for <strong>R-ETMPB</strong>, respectively.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120963"},"PeriodicalIF":3.3,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540272","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 : 2024-10-24DOI: 10.1016/j.jlumin.2024.120954
Michał Maciejewski , Karolina Milewska , Anna Synak , Marcin Łapiński , Wojciech Sadowski , Barbara Kościelska
Based on the developed phosphate glasses P2O5–K2O–Bi2O3–Nb2O5 doped with Eu3+, the influence of AlF3 and KF on the structural and luminescent properties was investigated. For this purpose, three series of glasses containing from 5 to 15 mol% fluorides were synthesized. Two of the series included the KF additive, which was introduced in two ways - proportionally and disproportionately at the expense of the K2O share. The structural characterization (XRD, FTIR) allowed us to determine the evolution of the internal structure of the glasses caused by changes in the type and content of the introduced additives and the presence of the Eu dopant. Similarly, using DSC/DTA, the thermal properties of undoped matrices were defined. The luminescence enhancement caused by the addition of ≥10 mol% fluorides was confirmed by the obtained fluorescence spectra. The presented studies not only expand the state of knowledge about the effects of fluorides on phosphate glasses but also demonstrate the ease of obtaining materials with improved properties suitable for use as phosphor in LEDs.
{"title":"Effect of AlF3 and KF addition on the structure and luminescent properties of P2O5 – K2O – Nb2O5 – Bi2O3 glasses doped with Eu3+","authors":"Michał Maciejewski , Karolina Milewska , Anna Synak , Marcin Łapiński , Wojciech Sadowski , Barbara Kościelska","doi":"10.1016/j.jlumin.2024.120954","DOIUrl":"10.1016/j.jlumin.2024.120954","url":null,"abstract":"<div><div>Based on the developed phosphate glasses P<sub>2</sub>O<sub>5</sub>–K<sub>2</sub>O–Bi<sub>2</sub>O<sub>3</sub>–Nb<sub>2</sub>O<sub>5</sub> doped with Eu<sup>3+</sup>, the influence of AlF<sub>3</sub> and KF on the structural and luminescent properties was investigated. For this purpose, three series of glasses containing from 5 to 15 mol% fluorides were synthesized. Two of the series included the KF additive, which was introduced in two ways - proportionally and disproportionately at the expense of the K<sub>2</sub>O share. The structural characterization (XRD, FTIR) allowed us to determine the evolution of the internal structure of the glasses caused by changes in the type and content of the introduced additives and the presence of the Eu dopant. Similarly, using DSC/DTA, the thermal properties of undoped matrices were defined. The luminescence enhancement caused by the addition of ≥10 mol% fluorides was confirmed by the obtained fluorescence spectra. The presented studies not only expand the state of knowledge about the effects of fluorides on phosphate glasses but also demonstrate the ease of obtaining materials with improved properties suitable for use as phosphor in LEDs.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120954"},"PeriodicalIF":3.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540268","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 : 2024-10-24DOI: 10.1016/j.jlumin.2024.120960
Dan-Yang Wang , Shan-Xiao Wang , Chao-Yang Tian, Li Wang, Rui-Ya Wang, Wen-Li Zhang, Xiao-Yu Li, Li-Hao Wang, Zhi-Cheng Du, Xiang-Wen Kong, Xiao-Wu Lei, Fang Yu
Pb-based halides are a highly promising class of materials due to their exceptional optoelectronic and magnetic properties. However, lead-based halides’ high toxicity and instability have detrimentally affected their actual applications. To address these issues, we investigated a lead-free one-dimensional manganese (Mn)-based organic–inorganic halide (TZI)MnCl3 (TZI = thiazolidin-3-ium). The red-emitting (TZI)MnCl3 demonstrated photoluminescence quantum yields of up to 46.4 % and 30.6 % when excited by light at wavelengths of 373 nm and 446 nm, respectively. Furthermore, (TZI)MnCl3 exhibited high stability under various conditions, highlighting its potential for optoelectronic applications.
{"title":"Synthesis and stability of one-dimensional red-emitting manganese-based Organic–inorganic halide","authors":"Dan-Yang Wang , Shan-Xiao Wang , Chao-Yang Tian, Li Wang, Rui-Ya Wang, Wen-Li Zhang, Xiao-Yu Li, Li-Hao Wang, Zhi-Cheng Du, Xiang-Wen Kong, Xiao-Wu Lei, Fang Yu","doi":"10.1016/j.jlumin.2024.120960","DOIUrl":"10.1016/j.jlumin.2024.120960","url":null,"abstract":"<div><div>Pb-based halides are a highly promising class of materials due to their exceptional optoelectronic and magnetic properties. However, lead-based halides’ high toxicity and instability have detrimentally affected their actual applications. To address these issues, we investigated a lead-free one-dimensional manganese (Mn)-based organic–inorganic halide (TZI)MnCl<sub>3</sub> (TZI = thiazolidin-3-ium). The red-emitting (TZI)MnCl<sub>3</sub> demonstrated photoluminescence quantum yields of up to 46.4 % and 30.6 % when excited by light at wavelengths of 373 nm and 446 nm, respectively. Furthermore, (TZI)MnCl<sub>3</sub> exhibited high stability under various conditions, highlighting its potential for optoelectronic applications.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120960"},"PeriodicalIF":3.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540274","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 : 2024-10-24DOI: 10.1016/j.jlumin.2024.120956
Shixuan Guo , Kejing Liu , Zihang Lin , Zhe Kang , Jinbo Liu , Ziang Yin , Zhuochen Cai , Yi Liu , Xianggang Zhang , Fa Luo , Shitao Xiong , Shusheng Wang , Xuxin He , Aizhong Yue , Qinghua Zhao , Rongrong Guo , Tao Wang
Despite the large interest in the scintillation properties of LaBr3:Ce, a detailed understanding of the underlying mechanism of temperature-dependence properties of Ce luminescence remains elusive. This study introduces a self-designed spectral apparatus to explore these properties in LaBr3:5%Ce. We observed a redshift phenomenon and band changes in the emission peak bands, indicating a reduction of the bond length between Ce and the host with increasing temperature. Moreover, the probability of low-energy peak emission decreases and the probability of high-energy peak emission increases, with increasing temperature was observed, suggesting a correlation with the proximity of Ce's 4f energy level to the valence band. Utilizing intensity parameters from the spectra, we identified the impact of temperature on LaBr3:Ce's self-absorption effect, revealing a significant self-absorption effect at the high-energy peak for the first time. A simple self-absorption model indicated that, despite high quantum efficiency of Ce, the overall self-absorption is minimal, establishing a correlation between the self-absorption coefficient of the high-energy peak and overall absorption. This research offers insights for developing radiation-resistant high-temperature luminescent devices and advances the field of high-temperature luminescent materials.
尽管人们对 LaBr3:Ce 的闪烁特性非常感兴趣，但对 Ce 发光特性随温度变化的基本机制的详细了解却仍然遥遥无期。本研究介绍了一种自行设计的光谱仪器，以探索 LaBr3:5%Ce 的这些特性。我们观察到了发射峰波段的红移现象和波段变化，这表明随着温度的升高，Ce 与宿主之间的键长缩短了。此外，我们还观察到随着温度的升高，低能峰发射的概率降低，而高能峰发射的概率升高，这表明这与 Ce 的 4f 能级接近价带有关。利用光谱中的强度参数，我们确定了温度对 LaBr3:Ce 自吸收效应的影响，首次揭示了高能峰存在显著的自吸收效应。一个简单的自吸收模型表明，尽管 Ce 的量子效率很高，但总体自吸收却很小，从而确立了高能峰自吸收系数与总体吸收之间的相关性。这项研究为开发抗辐射高温发光器件提供了启示，推动了高温发光材料领域的发展。
{"title":"Temperature dependence of Ce luminescence characteristics in LaBr3: Ce crystal","authors":"Shixuan Guo , Kejing Liu , Zihang Lin , Zhe Kang , Jinbo Liu , Ziang Yin , Zhuochen Cai , Yi Liu , Xianggang Zhang , Fa Luo , Shitao Xiong , Shusheng Wang , Xuxin He , Aizhong Yue , Qinghua Zhao , Rongrong Guo , Tao Wang","doi":"10.1016/j.jlumin.2024.120956","DOIUrl":"10.1016/j.jlumin.2024.120956","url":null,"abstract":"<div><div>Despite the large interest in the scintillation properties of LaBr<sub>3</sub>:Ce, a detailed understanding of the underlying mechanism of temperature-dependence properties of Ce luminescence remains elusive. This study introduces a self-designed spectral apparatus to explore these properties in LaBr<sub>3</sub>:5%Ce. We observed a redshift phenomenon and band changes in the emission peak bands, indicating a reduction of the bond length between Ce and the host with increasing temperature. Moreover, the probability of low-energy peak emission decreases and the probability of high-energy peak emission increases, with increasing temperature was observed, suggesting a correlation with the proximity of Ce's 4f energy level to the valence band. Utilizing intensity parameters from the spectra, we identified the impact of temperature on LaBr<sub>3</sub>:Ce's self-absorption effect, revealing a significant self-absorption effect at the high-energy peak for the first time. A simple self-absorption model indicated that, despite high quantum efficiency of Ce, the overall self-absorption is minimal, establishing a correlation between the self-absorption coefficient of the high-energy peak and overall absorption. This research offers insights for developing radiation-resistant high-temperature luminescent devices and advances the field of high-temperature luminescent materials.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120956"},"PeriodicalIF":3.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540365","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 : 2024-10-24DOI: 10.1016/j.jlumin.2024.120947
Itália V. Barbosa , Géraldine Dantelle , Célio V.T. Maciel , André L. Moura , Alain Ibanez , Lauro J.Q. Maia
Luminescence intensity ratio-based nanothermometry is a widely studied thermal sensing technique in the literature. Regarding biological purposes, it is essential to have thermal probes that are efficient in this type of environment. Thermal bioprobes demand highly crystallized nanocrystals, commonly smaller than 100 nm, with luminescence emissions in the near-infrared range that are not significantly absorbed by biological tissues. Several nanomaterials that have been studied for nanothermometry do not meet the requirements for this type of applications. Accordingly, researches are needed to develop suitable and reliable nanothermometers for thermal sensing. Therefore, our goal was to investigate the impact of Nd3+-Yb3+ co-doping on the thermometric performance of YAG matrix, a promising crystal because it presents a host structure favoring the insertion of lanthanide ions, which provide its luminescent features. In order to achieve this purpose, we first synthesized YAG:Nd3+-Yb3+ nanocrystals through a generic route - called modified Pechini method - to screen their thermal properties. Our results show that YAG:Nd3+-Yb3+ nanocrystals have the potential to work in vivo environments. The nanothermometers investigated here are excited in the first biological window (BW-I) at 805 nm with luminescence emissions within the BW-II, at 1030.5 and 1064 nm. By co-doping the YAG matrix with different Nd3+-Yb3+ concentrations, we studied the energy transfer process between the dopant ions and their impact on thermometry efficiency. By the efficient coupling of the Nd3+-Yb3+ pair, we improved the value by a factor of 3 of YAG compounds up to 0.6 %.K−1. We then synthesized YAG:Nd3+-Yb3+ nanocrystals using a second type of synthesis, by solvothermal means, in order to obtain individual nanocrystals, well dispersed in aqueous solutions, and to adapt their morphology and size for biological purposes. Therefore, we compared the structural and luminescence properties and thermometry efficiencies of YAG:Nd3+-Yb3+ nanocrystals obtained through two distinct processes and showed that the nanothermometry properties are not affected by the synthesis method.
{"title":"Comparison of YAG:Nd3+-Yb3+ nanothermometers synthesized by Pechini and solvothermal methods","authors":"Itália V. Barbosa , Géraldine Dantelle , Célio V.T. Maciel , André L. Moura , Alain Ibanez , Lauro J.Q. Maia","doi":"10.1016/j.jlumin.2024.120947","DOIUrl":"10.1016/j.jlumin.2024.120947","url":null,"abstract":"<div><div>Luminescence intensity ratio-based nanothermometry is a widely studied thermal sensing technique in the literature. Regarding biological purposes, it is essential to have thermal probes that are efficient in this type of environment. Thermal bioprobes demand highly crystallized nanocrystals, commonly smaller than 100 nm, with luminescence emissions in the near-infrared range that are not significantly absorbed by biological tissues. Several nanomaterials that have been studied for nanothermometry do not meet the requirements for this type of applications. Accordingly, researches are needed to develop suitable and reliable nanothermometers for thermal sensing. Therefore, our goal was to investigate the impact of Nd<sup>3+</sup>-Yb<sup>3+</sup> co-doping on the thermometric performance of YAG matrix, a promising crystal because it presents a host structure favoring the insertion of lanthanide ions, which provide its luminescent features. In order to achieve this purpose, we first synthesized YAG:Nd<sup>3+</sup>-Yb<sup>3+</sup> nanocrystals through a generic route - called modified Pechini method - to screen their thermal properties. Our results show that YAG:Nd<sup>3+</sup>-Yb<sup>3+</sup> nanocrystals have the potential to work in <em>vivo</em> environments. The nanothermometers investigated here are excited in the first biological window (BW-I) at 805 nm with luminescence emissions within the BW-II, at 1030.5 and 1064 nm. By co-doping the YAG matrix with different Nd<sup>3+</sup>-Yb<sup>3+</sup> concentrations, we studied the energy transfer process between the dopant ions and their impact on thermometry efficiency. By the efficient coupling of the Nd<sup>3+</sup>-Yb<sup>3+</sup> pair, we improved the <span><math><mrow><msub><mi>S</mi><mi>r</mi></msub></mrow></math></span> value by a factor of 3 of YAG compounds up to 0.6 %.K<sup>−1</sup>. We then synthesized YAG:Nd<sup>3+</sup>-Yb<sup>3+</sup> nanocrystals using a second type of synthesis, by solvothermal means, in order to obtain individual nanocrystals, well dispersed in aqueous solutions, and to adapt their morphology and size for biological purposes. Therefore, we compared the structural and luminescence properties and thermometry efficiencies of YAG:Nd<sup>3+</sup>-Yb<sup>3+</sup> nanocrystals obtained through two distinct processes and showed that the nanothermometry properties are not affected by the synthesis method.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120947"},"PeriodicalIF":3.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540281","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 : 2024-10-24DOI: 10.1016/j.jlumin.2024.120959
Yaolong Zhao , Bo Xu , Zhongfeng Duan , Aqiang Wang , Hui Qi , Shujie Wang , Binbin Hu
High efficiency, high brightness, and long-life quantum dot light-emitting diodes (QLEDs) are crucial for realizing integrated display and lighting applications. However, about 80% of the light is confined inside the device with substrate mode, waveguide mode, and plasma mode, which greatly weakens the brightness, efficiency and lifetime of the device. Here, a quasi-periodic concave template with large area was fabricated through the spontaneous condensation of droplets on the substrate surface. Based on the quasi-periodic template, SiO2 micro-lens arrays (SiO2-MLAs) Mie scattering composite structure was fabricated by imprinting on a SiO2-nanosphere thin film, which significantly improved light out-coupling at full angles with optimized quasi-Lambertian luminescence characteristics. In comparison to the planar QLED with state-of-the-art, the external quantum efficiency (EQE) demonstrated a qualitative improvement (>20%). Accordingly, the EQE, luminance (L), T50 lifetime (reduce to half brightness) of the green QLEDs with SiO2-MLAs structure have been optimized by 22%, 28%, 31%, and up to 24.21%, 381962.6 cd/m2, 111335 h, respectively. This strategy provides valuable insights into mass-producing and utilizing SiO2-MLA Mie scattering composite structures to boost QLED performance in high-efficiency display and lighting applications.
{"title":"Full-angle light out-coupling enhancement of quantum dot light-emitting diodes by Mie-scattering micro-lens arrays","authors":"Yaolong Zhao , Bo Xu , Zhongfeng Duan , Aqiang Wang , Hui Qi , Shujie Wang , Binbin Hu","doi":"10.1016/j.jlumin.2024.120959","DOIUrl":"10.1016/j.jlumin.2024.120959","url":null,"abstract":"<div><div>High efficiency, high brightness, and long-life quantum dot light-emitting diodes (QLEDs) are crucial for realizing integrated display and lighting applications. However, about 80% of the light is confined inside the device with substrate mode, waveguide mode, and plasma mode, which greatly weakens the brightness, efficiency and lifetime of the device. Here, a quasi-periodic concave template with large area was fabricated through the spontaneous condensation of droplets on the substrate surface. Based on the quasi-periodic template, SiO<sub>2</sub> micro-lens arrays (SiO<sub>2</sub>-MLAs) Mie scattering composite structure was fabricated by imprinting on a SiO<sub>2</sub>-nanosphere thin film, which significantly improved light out-coupling at full angles with optimized quasi-Lambertian luminescence characteristics. In comparison to the planar QLED with state-of-the-art, the external quantum efficiency (EQE) demonstrated a qualitative improvement (>20%). Accordingly, the EQE, luminance (L), T<sub>50</sub> lifetime (reduce to half brightness) of the green QLEDs with SiO<sub>2</sub>-MLAs structure have been optimized by 22%, 28%, 31%, and up to 24.21%, 381962.6 cd/m<sup>2</sup>, 111335 h, respectively. This strategy provides valuable insights into mass-producing and utilizing SiO<sub>2</sub>-MLA Mie scattering composite structures to boost QLED performance in high-efficiency display and lighting applications.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120959"},"PeriodicalIF":3.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540271","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 : 2024-10-23DOI: 10.1016/j.jlumin.2024.120957
Bingyan Qu , Changrui Zhu , Gaoliang Huang , Yang Jiang , Rulong Zhou , Lei Wang
In our traditional impressions, the emission spectra of Pb2+ ions usually fall predominantly within the UV region. In this work, we find when coordinated with haloid Cl− ions in CsCdCl3, the Pb2+ ions could demonstrate bright blue emission from 350 to 500 nm with maximum peaking at about 412 nm under the excitation of 250–320 nm light. This emission can be assigned to 3P1 → 1S0 transition of Pb2+ ions. More interestingly, this all-inorganic metal halide compound CsCdCl3:Pb2+ exhibits a long persistent luminescence (LPL) lasting 1050 s, endowed with application potential in the information storage and function of analysis and detection. The LPL mechanism of Pb2+ in CsCdCl3 has been studied by thermoluminescence (TL) measurements and the First-principle calculation, which dominate that the 6p levels of Pb2+ are just below the conduction band by about 0.6 eV. The excited electrons can travel across these 6p levels and the electron traps through the conduction band thermally, delaying the emission temporarily and producing the afterglow finally. Our finding in this work proves the potential of Pb2+ activated phosphors in visible region and provides a unique approach to construct Pb2+ doped LPL phosphors.
{"title":"Blue-emitting long-persistent luminescence phosphor Pb2+-doped CsCdCl3","authors":"Bingyan Qu , Changrui Zhu , Gaoliang Huang , Yang Jiang , Rulong Zhou , Lei Wang","doi":"10.1016/j.jlumin.2024.120957","DOIUrl":"10.1016/j.jlumin.2024.120957","url":null,"abstract":"<div><div>In our traditional impressions, the emission spectra of Pb<sup>2+</sup> ions usually fall predominantly within the UV region. In this work, we find when coordinated with haloid Cl<sup>−</sup> ions in CsCdCl<sub>3</sub>, the Pb<sup>2+</sup> ions could demonstrate bright blue emission from 350 to 500 nm with maximum peaking at about 412 nm under the excitation of 250–320 nm light. This emission can be assigned to <sup>3</sup>P<sub>1</sub> → <sup>1</sup>S<sub>0</sub> transition of Pb<sup>2+</sup> ions. More interestingly, this all-inorganic metal halide compound CsCdCl<sub>3</sub>:Pb<sup>2+</sup> exhibits a long persistent luminescence (LPL) lasting 1050 s, endowed with application potential in the information storage and function of analysis and detection. The LPL mechanism of Pb<sup>2+</sup> in CsCdCl<sub>3</sub> has been studied by thermoluminescence (TL) measurements and the First-principle calculation, which dominate that the 6p levels of Pb<sup>2+</sup> are just below the conduction band by about 0.6 eV. The excited electrons can travel across these 6p levels and the electron traps through the conduction band thermally, delaying the emission temporarily and producing the afterglow finally. Our finding in this work proves the potential of Pb<sup>2+</sup> activated phosphors in visible region and provides a unique approach to construct Pb<sup>2+</sup> doped LPL phosphors.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120957"},"PeriodicalIF":3.3,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540269","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 : 2024-10-23DOI: 10.1016/j.jlumin.2024.120961
A.K. Naumov , R.D. Aglyamov , V.V. Semashko
The optical and spectroscopic properties and laser performances of Nd3+:Na4Y6F22 fluoride single crystals were systematically examined. The quasi-CW laser action in Nd3+:Na4Y6F22 disordered crystals was realized for the first time under 796 nm-diode pumping. The slope efficiency was 5.8 % with a lasing threshold approximately 19 mW in terms of absorbed pumping power. The reasons for the discrepancy between the promising spectral-kinetic characteristics and pure lasing efficiency under diode pumping were elucidated.
{"title":"Evaluating Nd3+:Na4Y6F22 single crystals as a promising active medium for diode-pumped lasers","authors":"A.K. Naumov , R.D. Aglyamov , V.V. Semashko","doi":"10.1016/j.jlumin.2024.120961","DOIUrl":"10.1016/j.jlumin.2024.120961","url":null,"abstract":"<div><div>The optical and spectroscopic properties and laser performances of Nd<sup>3+</sup>:Na<sub>4</sub>Y<sub>6</sub>F<sub>22</sub> fluoride single crystals were systematically examined. The quasi-CW laser action in Nd<sup>3+</sup>:Na<sub>4</sub>Y<sub>6</sub>F<sub>22</sub> disordered crystals was realized for the first time under 796 nm-diode pumping. The slope efficiency was 5.8 % with a lasing threshold approximately 19 mW in terms of absorbed pumping power. The reasons for the discrepancy between the promising spectral-kinetic characteristics and pure lasing efficiency under diode pumping were elucidated.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120961"},"PeriodicalIF":3.3,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540282","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 : 2024-10-22DOI: 10.1016/j.jlumin.2024.120951
Shazma Ali, Muhammad Usman
The investigation of the optoelectronic performance of AlGaN-based ultraviolet-C (UV-C) micro light-emitting diodes (μLEDs) emitting at 273 nm is carried out numerically by reducing the chip area from large LED (300 × 300 μm2) to μLED (25 × 25 μm2). However, due to the high surface to volume ratio of μLED, surface recombination becomes dominant that is generated due to robust sidewall defects. The enhanced current spreading in μLED further affects the carrier injection in the active region as the electrons and holes are captured by sidewall defects. These effects are more dominant at low current density in μLED while at high current density, the sidewall defects get saturated, and the surface recombination weakens. Various optimization strategies, such as quantum wells (QWs) width, quantum barriers (QBs) width, and QW number are carried out to study the effect on the performance of 25 × 25 μm2 UV-C μLED. These optimization strategies at low current density (0.1 A/cm2) further improved the electrical/optical properties of AlGaN-based UV-C μLEDs.
{"title":"Dimensional downscaling and quantum engineering: A path to high-performance micro-LEDs","authors":"Shazma Ali, Muhammad Usman","doi":"10.1016/j.jlumin.2024.120951","DOIUrl":"10.1016/j.jlumin.2024.120951","url":null,"abstract":"<div><div>The investigation of the optoelectronic performance of AlGaN-based ultraviolet-C (UV-C) micro light-emitting diodes (μLEDs) emitting at 273 nm is carried out numerically by reducing the chip area from large LED (300 × 300 μm<sup>2</sup>) to μLED (25 × 25 μm<sup>2</sup>). However, due to the high surface to volume ratio of μLED, surface recombination becomes dominant that is generated due to robust sidewall defects. The enhanced current spreading in μLED further affects the carrier injection in the active region as the electrons and holes are captured by sidewall defects. These effects are more dominant at low current density in μLED while at high current density, the sidewall defects get saturated, and the surface recombination weakens. Various optimization strategies, such as quantum wells (QWs) width, quantum barriers (QBs) width, and QW number are carried out to study the effect on the performance of 25 × 25 μm<sup>2</sup> UV-C μLED. These optimization strategies at low current density (0.1 A/cm<sup>2</sup>) further improved the electrical/optical properties of AlGaN-based UV-C μLEDs.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120951"},"PeriodicalIF":3.3,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540278","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}
Owing to inherent structural instability of perovskite quantum dots, they are instability in humid environments and high temperatures conditions. To address this issue, a simple, environmentally friendly glass encapsulated technology is used to protect the perovskite quantum dots. Meanwhile, the dual-phase perovskite structure realized by phase transition engineering can further increase the stability of perovskite quantum dots. In this study, 3D CsPbBr3/0D Cs4PbBr6 dual-phase coexisting perovskite quantum dot glass powders were synthesized through melt quenching and subsequent crystallization induction of thermal treatment and water molecule, respectively. Results showed that compared with thermal treatment induction, perovskite QDs glass powders by water molecules induction exhibited a high PLQY of 24.7 % with a central wavelength of 519 nm and displayed excellent environmental stability. By combining green fluorescence from 3D CsPbBr3/0D Cs4PbBr6 QDs glass powders and red fluorescence powders (CaAlSiN3:Eu), a WLED device with an impressive EQE of 20.6 % was created, indicating a promising application potential.
{"title":"Dual-phase Cs4PbBr6/CsPbBr3 perovskite quantum dot borosilicate glass for WLED applications","authors":"Zhigang Yang, Shuqin Zhang, Junshuai Chen, Tianqing Sheng, Xinran Lv, Xuguang Wei, Guoqiang Qin, Gang Yu","doi":"10.1016/j.jlumin.2024.120953","DOIUrl":"10.1016/j.jlumin.2024.120953","url":null,"abstract":"<div><div>Owing to inherent structural instability of perovskite quantum dots, they are instability in humid environments and high temperatures conditions. To address this issue, a simple, environmentally friendly glass encapsulated technology is used to protect the perovskite quantum dots. Meanwhile, the dual-phase perovskite structure realized by phase transition engineering can further increase the stability of perovskite quantum dots. In this study, 3D CsPbBr<sub>3</sub>/0D Cs<sub>4</sub>PbBr<sub>6</sub> dual-phase coexisting perovskite quantum dot glass powders were synthesized through melt quenching and subsequent crystallization induction of thermal treatment and water molecule, respectively. Results showed that compared with thermal treatment induction, perovskite QDs glass powders by water molecules induction exhibited a high PLQY of 24.7 % with a central wavelength of 519 nm and displayed excellent environmental stability. By combining green fluorescence from 3D CsPbBr<sub>3</sub>/0D Cs<sub>4</sub>PbBr<sub>6</sub> QDs glass powders and red fluorescence powders (CaAlSiN<sub>3</sub>:Eu), a WLED device with an impressive EQE of 20.6 % was created, indicating a promising application potential.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120953"},"PeriodicalIF":3.3,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540279","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号