Wide-spectrum polarization-sensitive and fast-response photodetector based on 2D group Ⅳ-Ⅵ semiconductor tin selenide

Tin selenide(SnSe)has attracted considerable interest recently on account of its low-symmetry lattice structure,great compatibility with key semiconductor technology,and remarkable electrical and optical performance.SnSe-based polarization-sensitive photodetectors show promising application prospects because of their fast response and excellent photoelectric performance.Here,an in-plane anisotropic SnSe nanosheet was synthesized and reported in detail by applying angle-resolved polarized Raman spectroscopy(ARPRS),polarization-resolved optical microscopy(PROM),angle-resolved optical absorption spectroscopy(AROAS),and other crystal structure characterization methods.Moreover,SnSe crystals exhibit superior polarization detection performance with a high anisotropic photocurrent ratio(2.31 at 1064 nm)due to the structure formed by the Van der Waals superposition of covalently bonded atomic layers.Furthermore,SnSe-based photodetectors have high responsivity(9.27 A/W),high detectivity(4.08×10^(10)Jones),and fast response(in the order of nanoseconds).These results suggest a new method for fabricating 2D fast-response polarization-sensitive photodetectors in the future.

Optical and electronic anisotropy of a 2D semiconductor SiP

Two-dimensional anisotropic materials have been widely concerned by researchers because of their great application potential in the field of polarized detector devices and optical elements,which is a very important and popular research direction at present.As a IV-V two-dimensional material,silicon phosphide(SiP)has obvious in-plane anisotropy and exhibits excellent optical and electrical anisotropy properties.Herein,the optical anisotropy of SiP is studied by spectrometric ellipsometry measurements and polarization-resolved optical microscopy,and its electrical anisotropy is tested by SiP-based field-effect transistor.In addition,the normal and anisotropic photoelectric performance of SiP is shown by fabricating a photodetector and measuring it.In various measurements,SiP exhibits obvious anisotropy and good photoelectric performance.This work provides basic optical,electrical,and photoelectric performance information of SiP,and lays a foundation for further study of SiP and applications of SiP-based devices.