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

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 19; no. 33; pp. e2302443 - n/a
• Main Authors: Wu, Jianbo, Zhang, Xinyuan, You, Shihai, Zhu, Zeng‐Kui, Zhu, Tingting, Wang, Ziyang, Li, Ruiqing, Guan, Qianwen, Liang, Lishan, Niu, Xinyi, Luo, Junhua
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-08-2023
• Subjects: Anisotropy; Charge transport; chiral perovskites; Chirality; Circular polarization; circularly polarized light; Dark current; Detectors; Electric fields; Heterostructures; Nanotechnology; Optical communication; Perovskites; photodetection; Polarized light; photodetection; circularly polarized light; heterostructures; chiral perovskites
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202302443

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)2MAPb2I7/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.
Benefiting from the suppressed dark current and built‐in electric field, the chiral perovskite/Si heterostructure exhibits an impressive circularly polarized light distinguishability with a high anisotropy factor of 0.34 under the self‐driven mode, even the illumination power density down to 890 nW cm−2.