Low Detection Limit Circularly Polarized Light Detection Realized by Constructing Chiral Perovskite/Si Heterostructures

Abstract

Abstract Chiral perovskites have been demonstrated as promising candidates for direct circularly polarized light (CPL) detection due to their intrinsic chirality and excellent charge transport ability. However, chiral perovskite‐based CPL detectors with both high distinguishability of left‐ and right‐handed optical signals and low detection limit remain unexplored. Here, a heterostructure, (R‐MPA) 2 MAPb 2 I 7 /Si (MPA = methylphenethylamine, MA = methylammonium) is constructed, to achieve high‐sensitive and low‐limit CPL detection. The heterostructures with high crystalline quality and sharp interface exhibit a strong built‐in electric field and a suppressed dark current, not only improving the separation and transport of the photogenerated carriers but also laying a foundation for weak CPL signals detection. Consequently, the heterostructure‐based CPL detector obtains a high anisotropy factor up to 0.34 with a remarkably low CPL detection limit of 890 nW cm −2 under the self‐driven mode. As a pioneering study, this work paves the way for designing high‐sensitive CPL detectors that simultaneously have great distinguishing capability and low detection limit of CPL.