Phase Stabilized α‐CsPbI3 Perovskite Nanocrystals for Photodiode Applications

Abstract

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.