Phase Stabilized α‐CsPbI3 Perovskite Nanocrystals for Photodiode Applications

High-performance and high-reliability photodiodes are demonstrated by using α-CsPbI3 perovskite nanocrystals (NCs) phase-stabilized with a low-temperature solution-treated active layer. In addition to the high charge mobility, the high absorption coefficient, and IR-blind characteristics of the perovskite material, the defect-tolerant nature of α-CsPbI3 perovskite NCs are combined to realize hysteresis-free and high detectivity photodiodes. To further minimize interface defects originating from multi-layer photodiode construction, a poly(3-hexylthiophene) layer is strategically introduced as a passivation and electron blocking layer, resulting in a low diode ideality factor of 1.5 and a noise equivalent power of 1.6 × 10−13 W Hz−0.5. As a result, high detectivity of 1.8 × 1012 Jones is demonstrated with near-zero hysteresis. Furthermore, the optimized photodiode exhibits excellent stability under high humidity conditions owing to the intrinsic nature of the defect-tolerant α-CsPbI3 perovskite NCs.