In-Sublattice Carrier Transition Enabled Polarimetric Photodetectors with Reconfigurable Polarity Transition.

Li, Dongyan; Li, Zexin; Sun, Yan; Zhou, Jian; Xu, Xiang; Wang, Haoyun; Chen, Yunxin; Song, Xingyu et al. · Adv Mater · 2024

basic_science · Level V

Where this comes from

Abstract

Miniaturized polarimetric photodetectors based on anisotropic two-dimensional materials attract potential applications in ultra-compact polarimeters. However, these photodetectors are hindered by the small polarization ratio values and complicated artificial structures. Here, a novel polarization photodetector based on in-sublattice carrier transition in the CdSb<sub>2</sub>Se<sub>3</sub>Br<sub>2</sub>/WSe<sub>2</sub> heterostructure, with a giant and reconfigurable PR value, is demonstrated. The unique periodic sublattice structure of CdSb<sub>2</sub>Se<sub>3</sub>Br<sub>2</sub> features an in-sublattice carrier transition preferred along Sb<sub>2</sub>Se<sub>3</sub> chains. Leveraging on the in-sublattice carrier transition in the CdSb<sub>2</sub>Se<sub>3</sub>Br<sub>2</sub>/WSe<sub>2</sub> heterostructure, gate voltage has an anisotropic modulation effect on the band alignment of heterostructure along sublattice. Consequently, the heterostructure exhibits a polarization-tunable photo-induced threshold voltage shift, which provides reconfigurable PR values from positive (unipolar regime) to negative (bipolar regime), covering all possible numbers (1→+∞/-∞→-1). Using this anisotropic photovoltaic effect, gate-tunable polarimetric imaging is successfully implemented. This work provides a new platform for developing next-generation highly polarimetric optoelectronics.