Lejing Pi, Chunguang Hu, Wanfu Shen, Liang Li, Peng Luo, Xiaozong Hu, Ping Chen, Dongyan Li, Zexin Li, Xing Zhou*, and Tianyou Zhai*, Highly In-Plane Anisotropic 2D PdSe2 for Polarized Photodetection with Orientation Selectivity, Advanced Functional Materials 2020, 31, 2006774.
https://doi.org/10.1002/adfm.202006774.
Abstract: Polarized photodetection based on anisotropic two-dimensional materials display promising prospects for the practical application in optical communication and optoelectronic fields. However, most of the reported polarized photodetection are limited by the lack of valid tunable strategy and low linear dichroism ratio. A peculiar noble metal dichalcogenide—PdSe2 with a puckered pentagonal structure and abnormal linear dichroism conversion—potentially removes these restrictions and is demonstrated in this study. Herein, azimuth-dependent reflectance difference microscopy combined with anisotropic electrical transport measurements indicate strong in-plane anisotropic optical and electrical properties of two-dimensional PdSe2. Remarkably, the typical polarization-resolved photodetection exhibits anisotropic photodetection characteristics with the dichroic ratio up to ~1.8 at 532 nm and ~ 2.2 at 369 nm, and their dominant polarization orientation differs by 90° corresponding to the a-axis and b-axis, respectively. The unique orientation selection behavior in polarization-dependent photodetection can be attributed to the intrinsic linear dichroism conversion. Our results make 2D PdSe2 a promising platform for investigating anisotropic structure–property correlations and integrated optical applications for novel polarization-sensitive photodetection.
