The two-dimensional(2 D) Ruddlesden–Popper-type perovskites, possessing tunable bandgap, narrow light emission,strong quantum confinement effect, as well as a simple preparation method, are identified as a new genera...The two-dimensional(2 D) Ruddlesden–Popper-type perovskites, possessing tunable bandgap, narrow light emission,strong quantum confinement effect, as well as a simple preparation method, are identified as a new generation of candidate materials for efficient light-emitting diodes. However, the preparation of high-quality quasi-2 D perovskite films is still a challenge currently, such as the severe mixing of phases and a high density of defects within the films, impeding the further promotion of device performance. Here, we prepared the quasi-2 D PEA_(2) MA_(n-1) Pbn Br_(3 n+1) perovskite films by a modified spin-coating method, and the phases with large bandgap were effectively suppressed by the vacuum evaporation treatment. We systematically investigated the optical properties and stability of the optimized films, and the photoluminescence(PL) quantum yield of the treated films was enhanced from 23% to 45%. We also studied the emission mechanisms by temperature-dependent PL spectra. Moreover, the stability of films against moisture, ultraviolet light, and heat was also greatly improved.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11774318, 12074347, 12004346, and 61935009)the Open Fund of State Key Laboratory of Integrated Optoelectronics (Grant No. IOSKL2020KF04)。
文摘The two-dimensional(2 D) Ruddlesden–Popper-type perovskites, possessing tunable bandgap, narrow light emission,strong quantum confinement effect, as well as a simple preparation method, are identified as a new generation of candidate materials for efficient light-emitting diodes. However, the preparation of high-quality quasi-2 D perovskite films is still a challenge currently, such as the severe mixing of phases and a high density of defects within the films, impeding the further promotion of device performance. Here, we prepared the quasi-2 D PEA_(2) MA_(n-1) Pbn Br_(3 n+1) perovskite films by a modified spin-coating method, and the phases with large bandgap were effectively suppressed by the vacuum evaporation treatment. We systematically investigated the optical properties and stability of the optimized films, and the photoluminescence(PL) quantum yield of the treated films was enhanced from 23% to 45%. We also studied the emission mechanisms by temperature-dependent PL spectra. Moreover, the stability of films against moisture, ultraviolet light, and heat was also greatly improved.
