Enhancing negative thermal quenching in green-emitting perovskite microspheres via shallow trap state modulation  

浅陷阱态调控增强绿色发光钙钛矿微球的负热猝灭效应

作　　者：Zhenxu Lin Rui Huang Jie Song Yi Zhang Zewen Lin Hongliang Li Haixia Wu Dejian Hou Yanqing Guo Jing Wang Paul K.Chu 林圳旭;黄锐;宋捷;张毅;林泽文;李洪亮;吴海霞;侯得健;郭艳青;王静;朱剑豪(School of Materials Science and Engineering,Hanshan Normal University,Chaozhou 521041,China;Ministry of Education Key Laboratory of Bioinorganic and Synthetic Chemistry,State Key Laboratory of Optoelectronic Materials and Technologies,Sun Yat-Sen University,Guangzhou 510275,China;Department of Physics,Department of Materials Science and Engineering,and Department of Biomedical Engineering,City University of Hong Kong,Tat Chee Avenue,Kowloon,Hong Kong,China)

机构地区：[1]School of Materials Science and Engineering,Hanshan Normal University,Chaozhou 521041,China [2]Ministry of Education Key Laboratory of Bioinorganic and Synthetic Chemistry,State Key Laboratory of Optoelectronic Materials and Technologies,Sun Yat-Sen University,Guangzhou 510275,China [3]Department of Physics,Department of Materials Science and Engineering,and Department of Biomedical Engineering,City University of Hong Kong,Tat Chee Avenue,Kowloon,Hong Kong,China

出　　处：《Science China Materials》2025年第1期149-155,共7页中国科学(材料科学)(英文版)

基　　金：supported by Guangdong Basic and Applied Basic Research Foundation;Research Projects of Department of Education of Guangdong Province (2021ZDJS039 and 2024ZDZX1026);City University of Hong Kong Donation Research Grants (9220061 and DON-RMG 9229021)。

摘　　要：For luminescent materials,negative thermal quenching(NTQ),characterized by an increase in the luminescent intensity with temperature,has a large potential in lighting and display technologies.However,leveraging NTQ in metal halide perovskites is challenging,and the mechanism is not well understood.Herein,by utilizing low-temperature photoluminescence,persistent luminescence and thermoluminescence,the origins of NTQ in CsPbBr_(3) microspheres are systematically studied,which pertain to the liberation of carriers from shallow trap states.Experimental and theoretical investigations reveal that the energy of these shallow defect states is approximately 0.135 eV beneath the conduction band.A rapid thermal treatment increases the density of these shallow traps and amplifies the NTQ effect,resulting in an enhancement of room-temperature photoluminescence by more than 60%compared to that at 150 K.The process also reduces the threshold for amplified spontaneous emission to about 45 W/cm^(2).Our findings not only provide a deeper understanding of the NTQ phenomenon in CsPbBr3 microspheres but also open new avenues for enhancing the performance of perovskite optoelectronic devices through energy state regulation.发光材料中的负热猝灭(NTQ)现象,表现为随温度升高发光强度增加,在照明和显示技术中具有广泛应用前景.然而,在金属卤化物钙钛矿中实现NTQ具有一定挑战性,其机制尚不完全清楚.本研究通过低温光致发光、长余辉和热释光谱技术,系统研究了CsPbBr3微球中NTQ现象的起源.结果表明, NTQ现象与浅陷阱态中载流子的释放密切相关.实验与理论分析揭示,这些浅缺陷态的能级位于导带下方约0.135 eV处.快速热处理可显著增加浅陷阱的密度,从而增强NTQ效应,使室温下的光致发光强度较150 K时提高了60%以上.同时,该处理将受激自发辐射的阈值降低至约45 W/cm^(2).本研究不仅加深了对CsPbBr3微球中NTQ机制的理解,也为通过能态调控提升钙钛矿光电子器件性能开辟了新途径.

关 键 词：negative thermal quenching photoluminescence CsPbBr3 microsphere amplified spontaneous emission low threshold 

分 类 号：TB34[一般工业技术—材料科学与工程]