Photonics Research, 2020, 8 (7): 07001086, Published Online: Jun. 3, 2020
Ultrapure and highly efficient green light emitting devices based on ligand-modified CsPbBr3 quantum dots Download: 779次
Abstract
All inorganic perovskite quantum dots (QDs) have been recognized as promising optical materials to fabricate green light emission devices because of their excellent optical performance. However, regular QDs with an oleic acid (OA) ligand show poor stability, which limits their practical application. We replaced the OA ligand in QDs with a 2-hexyldecanoic acid (DA) ligand and, in the synthesis, found that the new material has better optical properties than regular QDs ( QDs). Due to the strong binding energy between the DA ligand and QDs, the ligand-modified QDs ( QDs) show a high photoluminescence quantum yield (PLQY) of 96%, while the PLQY of QDs is 84%. Subsequently, the QDs coated on the blue light-emitting diode (LED) chips as green phosphors are demonstrated. The color conversion from blue to pure green is achieved by adding the QDs solution up to 60 μL, while the pure green emission devices only need 18 μL QDs solution under the same concentration. The ultrapure, highly efficient green light-emitting devices based on QDs exhibit a luminous efficiency of 43.6 lm/W with a CIE (0.2086, 0.7635) under a 15.3 mA driving current. In addition, the green emission wavelength of the devices based on QDs almost has no shift, even under a high injection current. These results highlight the promise of DA ligand-modified QDs for light-emitting devices and enrich the application field of ligand-modified QDs.
Dongdong Yan, Shuangyi Zhao, Huaxin Wang, Zhigang Zang. Ultrapure and highly efficient green light emitting devices based on ligand-modified CsPbBr3 quantum dots[J]. Photonics Research, 2020, 8(7): 07001086.