摘要
The production of high-quality eco-friendly quantum dots(QDs)is challenging because of the efficient yet elusive nonradiative recombination within.This study examined the effects of cooling engineering on regulating the excited states to realize high-quality ZnSeTe core-shell QDs.The presence of ultrafast hot-carrier trapping and band-edge carrier trapping is responsible for the poor emission efficiency in ZnSeTe QDs.The above processes can be suppressed simultaneously by engineering the cooling process,and the underlying mechanisms are interrogated by combined electronic and spectroscopic characterization.The engineered ZnSeTe QDs exhibited record-high efficiency(>90%)and stability that were comparable to those of the canonical CdSe QDs.Leveraging on the achievement,the ZnSeTe QD-based white light-emitting diodes(WLEDs)showed excellent optical performance,including a high color-rendering index of 80 and an appropriate correlated color temperature of 7391 K.Furthermore,the WLEDs could serve as light sources in ecofriendly visible light communication.These results highlight the feasibility of eco-friendly QDs for practical applications without environmental hazards.
由于材料内部存在高效的非辐射复合,这使得实现高质量的环保量子点仍然具有挑战性.本文中,我们探索了通过冷却工程调节激发态对实现高质量的ZnSeTe核壳量子点的影响.研究发现,超快热载流子俘获和带边载流子俘获是ZnSeTe量子点发射效率低下的主要原因.我们通过设计冷却工程抑制上述过程,并且结合电子和光谱表征分析了其潜在机制.经过冷却优化的ZnSeTe量子点表现出高量子发光效率(>90%)和稳定性,这可与经典的CdSe量子点相媲美.基于这种量子点的白光发光二极管(WLED)表现出优异的光学性能,包括高显色指数(80)和良好的相关色温(7391 K).此外,高性能的WLED还可以用作环保可见光通信.这些结果表明了环保量子点在实际应用中的可行性.
作者
Baoqiang Wu
Shuangyi Zhao
Mingshui Zhang
Zhigao Huang
Chen Chen
Zhigang Zang
Yue Wang
吴保强;赵双易;张明水;黄志高;陈晨;臧志刚;王跃(MIIT Key Laboratory of Advanced Display Materials and Devices,Institute of Optoelectronics&Nanomaterials,College of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;Key Laboratory of Optoelectronic Technology&Systems(Ministry of Education),Chongqing University,Chongqing 400044,China;School of Microelectronics and Communication Engineering,Chongqing University,Chongqing 400044,China)
基金
supported by the National Natural Science Foundation of China(11904172)
Natural Science Foundation of Jiangsu Province(BK20190446)
support of the start-up funding from Nanjing University of Science and Technology。
作者简介
These authors contributed equally to this work:Baoqiang Wu received his B.S.degree from Wuhan University of Science and Technology in 2019.He is now studying for a master’s degree in the School of Materials Science and Engineering at Nanjing University of Science and technology.His main research is the preparation and application of cadmium-free semiconductor nanocrystals;These authors contributed equally to this work:Shuangyi Zhao received his B.S.degree from Shandong University in 2013 and Ph.D.degree from the State Key Lab of Silicon Materials at Zhejiang University in 2018.He is now a postdoctoral researcher in the College of Optoelectronic Engineering at Chongqing University.His research concerns the fabrication of semiconductor nanocrystals,including lead-halide and lead-free perovskites,and their applications in optoelectronic devices;These authors contributed equally to this work:Mingshui Zhang received his B.S.degree at Nanjing University of Science and Technology in 2020.He is now studying for a master’s degree in the School of Materials Science and Engineering at Nanjing University of Science and Technology.His main research is the preparation and application of perovskite core-shell nanocrystals;Corresponding author:Yue Wang received his Ph.D.degree in physics from Nanyang Technological University.He is currently working at the School of Materials Science and Engineering,Nanjing University of Science and Technology.His research interests include optical spectroscopy,semiconductor photophysics,and optically pumped lasers.email:ywang@njust.edu.cn。
