Ultra-broadband,fast,and polarization-sensitive photoresponse of low-symmetry 2D NdSb_(2)

Broadband photodetectors with polarization-sensitive ability have received extraordinary attention for modern optoelectronic devices.Ideal photodetectors should possess high responsivity,fast response,and good stability,which are rare to meet at the same time in one low-symmetric two-dimentional(2D)material.In this work,neodymium diantimonides(RSb_(2)),a member of light rare-earth diantimonides RSb_(2)(R=La–Nd,Sm)with low-symmetry structure,is introduced as a fascinating highly anisotropic 2D material for broadband detection(532 nm to 4μm).The photodetector exhibits a responsivity of 0.49 mA·W^(−1)with 15μs response time at 532 nm and highly stable performance under ambient conditions over 8 months.Furthermore,we identify the polarization-sensitive photoresponse of the detector and demonstrate a high anisotropic factor~1.6.In addition,strong inplane anisotropy is revealed by anisotropic phonon response and the photodetection mechanism is investigated by scanning photocurrent microscopy measurements.This pioneer work on RSb_(2)paves the way for further exploration of 2D RSb_(2)for high performance polarized photodetectors with fast photothermoelectric response.