Affiliation:
1. State Key Laboratory of Pulsed Power Laser Technology/Advanced Laser Technology Laboratory of Anhui Province National University of Defense Technology Hefei People's Republic of China
2. School of Materials Science and Engineering Hefei University of Technology Hefei People's Republic of China
3. College of Physical Science and Technology/Microelectronics Industry Research Institute Yangzhou University Yangzhou People's Republic of China
4. School of Electrical Engineering and Automation Hefei University of Technology Hefei People's Republic of China
Abstract
AbstractAnion exchange is an effective strategy to regulate the composition and optoelectronic properties of perovskite quantum dots (PQDs). Though promising, it is more desirable to synthesize PQDs to avoid the decrease of photoluminescence quantum yield (PLQY). Herein, we developed a ligand mediated anion exchange approach, in which the phase transition from CsPbBr3 QDs to CsPbI3 QDs was observed with the introduction of N‐Acetyl‐l‐cysteine (NAC) and 1,3‐dimethylimidazolium iodide (DMII) aqueous solution in CsPbBr3 QDs solution. NAC is expected to create more halogen vacancies in CsPbBr3 QDs, which provides sufficient adsorption sites for I− ions, resulting in accelerating the anion exchange rate in the process of DMII incorporation. Benefiting from the synergistic ligand mediated anion exchange, high PLQY of 97% and remarkable stability of CsPbI3 QDs are obtained. Furthermore, a white light‐emitting diode (WLED) with a lumen efficiency (LE) of 116.82 lm/W is constructed, showing remarkable stability under continuous operation.image
Funder
State Key Laboratory of Pulsed Power Laser Technology
National Natural Science Foundation of China
China Postdoctoral Science Foundation
Natural Science Foundation of Anhui Province