Owing to their environmentally friendly characteristic, InP-based quantum dots (QDs) show great potential in various fields as an alternative to Cd-based QDs. However, the current mainstream synthesis process, the (TMS)3P-based injection method, still faces many challenges, such as the high cost of (TMS)3P and complex temperature control. In contrast, the solvothermal method is considered to be more feasible and reproducible. Despite its potential advantages, little has been done to understand how the precursors influence the synthesis of InP QDs using the solvothermal method. In this research, InZnP/ZnS QDs were synthesized using practical phosphorus precursors (DEA)3P or (DMA)3P. Through the feasible regulation of zinc, indium, phosphorus and sulfur precursors, the band gap of the QDs could be widely and accurately tuned, and a much wider photoluminescence wavelength ranging from 484 nm to 651 nm could be achieved. Furthermore, InI3 and InBr3 contributed to the blueshift in the PL wavelengths, and the combination of (DEA)3P, (DMA)3P, n-DDT and t-DDT refined the PL wavelength with a small tuning gap of 5 nm.
Fei Gao,Xiaonan Zhu,Qiushi Feng,Weiheng Zhong,Weizhen Liu,Haiyang Xu,Yichun Liu
Lead-free metal halide perovskites are promising materials for future optoelectronic application , which have recently attracted great attention for their environmental-friendliness and excellent light emission properties. However, the development of deep-blue emission lead-free halide perovskite nanocrystal is still far behind in performance in comparison with its red/green counterparts. Herein, the lead-free Cs 3 Cu 2 I 5 nanocrystals are prepared via a modified hot-injection strategy. By adding InI 3 as precursor, the synthesized Cs 3 Cu 2 I 5 single-phase nanocrystals show a bright deep-blue emission peaked at ~440 nm, with a record high photoluminescence quantum yield (PL QY) up to 96.6% at an optimized InI 3 content of 0.15 mmol. The InI 3 additive contributes to the high PL QY through both iodide vacancy reparation of I - ions and size-controlled growth of In 3+ ions. First principle calculations reveal that the broadband blue emission originates from self-trapped excitons in Cs 3 Cu 2 I 5 , which are formed due to the excited-state lattice expansion and Cu-I bond lengthening of [Cu 2 I 5 ] 3- cluster under light excitation . The good stabilities of these Cs 3 Cu 2 I 5 nanocrystals against heat, water, UV irradiation and environmental storage are also investigated experimentally and theoretically in detail. For application demonstration, light-emitting devices are manufactured by using these Cs 3 Cu 2 I 5 nanocrystals powder as phosphor, which exhibit good working stability with a half-lifetime over 300 h. Besides, the Cs 3 Cu 2 I 5 nanocrystals solution is also utilized as fluorescent ink, and the printed patterns can maintain anti-counterfeiting features even after treatment by heating and long-term environmental storage, indicating the robustness of these Cs 3 Cu 2 I 5 nanocrystals for potential anti-counterfeiting application.
危险品化学品经营许可证（带存储）