In‐Sublattice Carrier Transition Enabled Polarimetric Photodetectors with Reconfigurable Polarity Transition

Abstract

AbstractMiniaturized 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 CdSb2Se3Br2/WSe2 heterostructure, with a giant and reconfigurable PR value, is demonstrated. The unique periodic sublattice structure of CdSb2Se3Br2 features an in‐sublattice carrier transition preferred along Sb2Se3 chains. Leveraging on the in‐sublattice carrier transition in the CdSb2Se3Br2/WSe2 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.