Phase Stabilized α‐CsPbI₃ Perovskite Nanocrystals for Photodiode Applications

High‐performance and high‐reliability photodiodes are demonstrated by using α‐CsPbI 3 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‐CsPbI 3 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 × 10 12 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‐CsPbI 3 perovskite NCs.