Patterned Chiral Perovskite Film for Self‐Driven Stokes Photodetectors

RESEARCH ARTICLE www.afm-journal.de Patterned Chiral Perovskite Film for Self-Driven Stokes Photodetectors Chao Wang, Guoyi Li, Zhipeng Dai, Wei Tian,* and Liang Li* Polarization detection plays an essential role in a wide range of fields, including target identification, 3D reconstruction, and robotic vision. Self-driven on-chip full-Stokes photodetectors are urgently required to meet the trend of miniaturization and integration. Nevertheless, how to fulfill efficient circular and linear polarimetry simultaneously with sufficient recognition effectiveness in a compact device is a great challenge. Herein, a patterned chiral perovskite film is fabricated by imprinting strategy, and vertically-structured self-driven Stokes photodetector is demonstrated, which can recognize various polarization states at 0 V. Through patterned design of the chiral perovskite film by integrating circle and nanowire structure, flexible tuning of circular and linear polarization components within the detector is achieved, enabling the detector to strike a balance between circular and linear polarization detection ability when recognizing arbitrary polarization light. The maximum circular polarization sensitivity factor and linear polarization ratio can reach 0.125 and 1.5, respectively. By optimizing well-defined patterned shape, the resultant detector can recognize polarized light with an average recognition error <7%. This work opens an avenue toward the fabrication of self-driven filterless Stokes detectors based on patterned chiral perovskite film for accurate detection of arbitrary polarization states. 1. Introduction Light, as an optimal information carrier, not only conveys data through the full utilization of its intensity and color signals for information transmission but also leverages its polarization state to transmit and distinguish signals. The detection of polarized light has opened up a novel avenue for target recognition in in- tricate environments.[1–8] In recent years, there has been signif- icant progress in the development of on-chip polarization de- tectors featured by ultracompact structures and high integration density.[9–13] These full-Stokes detectors rely on either coupling a polarization-unresolved photodetector with a comprehensive C. Wang, G. Li, Z. Dai, W. Tian, L. Li School of Physical Science and Technology Jiangsu Key Laboratory of Thin Films Center for Energy Conversion Materials & Physics (CECMP) Soochow University Suzhou 215006, China E-mail: wtian@suda.edu.cn;lli@suda.edu.cn The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adfm.202316265 DOI: 10.1002/adfm.202316265 plasmonic metasurface/grating or integrat- ing an individual microretarder layer atop a linear polarization layer for the extraction of various polarization components. However, the additional filtering layers would not only add the complexity of the system and device cost but also cause unnecessary energy loss. In this scenario, it is desired to further sim- plify the device configuration and explore filterless full-Stokes detectors for integrated optoelectronic applications. Chiral halide perovskites, which can be synthesized by intentionally introducing chirality via chiral molecules, possess both chirality and remarkable optoelectronic properties, enabling them as promising candidates for high-performance opti- cal, electronic, and spintronic device applications.[14–18] Due to their unique mi- cro helical structure, chiral perovskite has become a promising building block in cir- cular polarized light (CPL) detection.[19–21] Meanwhile, appropriate templates can endow perovskite thin film nanowire arrays with good optical anisotropy for sens- ing linearly polarized light.[22] Although Stokes photodetectors have been realized by utilizing chiral perovskite nanowire array, achieving efficient linear and circu- lar polarimetry simultaneously on the same detection material chip still remains a challenge. As the