Solution-Processed UV Photodiodes Based on Cs2Ag0.35Na0.65InCl6 Perovskite Nanocrystals

Halide perovskites stand out as promising materials for the realization of high-performance photodetectors. However, the inherent instability and lead toxicity are still obstacles facing the wide practical application of photodetectors. In this work, the first highly responsive lead-free perovskite photodiode based on Cs2Ag0.35Na0.65InCl6 nanocrystals (NCs) is demonstrated. The composition tuning strategy is introduced to enhance the device performance of photodiodes. Employed with a device structure composed of ZnO:Al electron-transport layer and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-s-butylphenyl)diphenylamine)] hole transport layer, lead-free perovskite NC photodiodes exhibit a high responsivity of 3.03 A/W and specific detectivity of 1.29 × 1011 Jones under the illumination of a 340 nm light source. Moreover, the ultraviolet (UV) photodiodes show good performance under the self-powered mode, which exhibits a responsivity of 0.07 A/W and a specific detectivity of 5.04 × 1010 Jones. Our work verifies the great potential of the Cs2Ag0.35Na0.65InCl6 NCs in the application of environmentally friendly and high-performance UV photodiodes.