Quantum tailoring for polarization-discriminating BiS nanowire photodetectors and their multiplexing optical communication and imaging applications.

In this study, cost-efficient atmospheric pressure chemical vapor deposition has been successfully developed to produce well-aligned high-quality monocrystalline BiS nanowires. By virtue of surface strain-induced energy band reconstruction, the BiS photodetectors demonstrate a broadband photoresponse across 370.6 to 1310 nm. Upon a gate voltage of 30 V, the responsivity, external quantum efficiency, and detectivity reach 23 760 A W, 5.55 × 10%, and 3.68 × 10 Jones, respectively. The outstanding photosensitivity is ascribed to the high-efficiency spacial separation of photocarriers, enabled by synergy of the axial built-in electric field and type-II band alignment, as well as the pronounced photogating effect. Moreover, a polarization-discriminating photoresponse has been unveiled. For the first time, the correlation between quantum confinement and dichroic ratio is systematically explored. The optoelectronic dichroism is established to be negatively correlated with the cross dimension (, width and height) of the channel. Specifically, upon 405 nm illumination, the optimized dichroic ratio reaches 2.4, the highest value among the reported BiS photodetectors. In the end, proof-of-concept multiplexing optical communications and broadband lensless polarimetric imaging have been implemented by exploiting the BiS nanowire photodetectors as light-sensing functional units. This study develops a quantum tailoring strategy for tailoring the polarization properties of (quasi-)1D material photodetectors whilst depicting new horizons for the next-generation opto-electronics industry.