Toward Efficient Two‐Photon Circularly Polarized Light Detection through Cooperative Strategies in Chiral Quasi‐2D Perovskites

RESEARCH ARTICLE www.advancedscience.com Toward Efficient Two-Photon Circularly Polarized Light Detection through Cooperative Strategies in Chiral Quasi-2D Perovskites Wentao Wu, Xiaoying Shang, Zhijin Xu, Huang Ye, Yunpeng Yao, Xueyuan Chen, Maochun Hong, Junhua Luo, and Lina Li* Organic–inorganic hybrid perovskites carry unique semiconducting properties and advanced flexible crystal structures. These characteristics of organic–inorganic hybrid perovskites create a promising candidacy for circularly polarized light (CPL) detection. However, CPL detections based on chiral perovskites are limited to UV and visible wavelengths. The natural quantum well structures of layered hybrid perovskites generate strong light–matter interactions. This makes it possible to achieve near-infrared (NIR) CPL detection via two-photon absorption in the sub-wavelength region. In this study, cooperative strategies of dimension increase and mixed spacer cations are used to obtain a pair of chiral multilayered perovskites (R-𝜷-MPA)EA2Pb2Br7 and (S-𝜷-MPA)EA2Pb2Br7 (MPA = methylphenethylammonium and EA = ethylammonium). The distinctive bi-cations interlayer and multilayered inorganic skeletons provide enhanced photoconduction. Moreover, superior photoconduction leads to the prominent NIR CPL response with a responsivity up to 8.1 × 10−5 A W−1. It is anticipated that this work can serve as a benchmark for the fabrication and optimization of efficient NIR CPL detection by simple chemical design. 1. Introduction Organic–inorganic hybrid perovskites have been widely used in for photoelectronic applications because of their excellent photoelectronic properties. These properties include low defect W. Wu, Z. Xu, H. Ye, Y. Yao, M. Hong, J. Luo, L. Li State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fuzhou, Fujian 350002, P. R. China E-mail: lilina@fjirsm.ac.cn X. Shang, H. Ye, X. Chen, M. Hong, J. Luo, L. Li University of Chinese Academy of Sciences Beijing 100049, P. R. China The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/advs.202206070 © 2023 The Authors. Advanced Science published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. DOI: 10.1002/advs.202206070 density,[1] long carrier diffusion,[2–5] and high optical absorption coefficient.[6] It is worth noting that the structural flexibility of low-dimensional perovskites allows chiral organic cations to be inserted into perovskite layers to endow chirality.[7] The chiral optical activity of perovskites can be realized through the transfer of chirality from the organic cations to the inorganic skeletons.[8] Therefore, the di- rect detection of circularly polarized light (CPL) using 2D chiral perovskites has attracted great attention in the fields of chiroptoelectronics.[9–15] Tang et al. re- alized high-performance CPL detection employing chiral hybrid perovskites, (R-/S- 𝛼-MBA)PbI4 (MBA = phenylethylamine).[9] Wu group using a 2D chiral perovskite nanowires achieved Stokes photodetection with impressive detectivity.[11] Despite those significant achievements, most of the CPL photodetections based on chiral perovskites can only work in UV and visible wavelengths. The main reason is that the typical chiral 2D perovskites exhibit chiral optical inactivity in the near-infrared (NIR) region limited by their optical bandgap. As a nonlinear optical process, two-photon absorption can convert light with photon energies below the bandgap into electrical signals and has been widely used in sub-bandgap X. Shang, X. Chen CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Key Laboratory of Nanomaterials Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fuzhou,