2D Magnetic Fe_(0.75)Ta_(0.5)S_2: Giant Exchange Bias with Broadband Photoresponse

摘要

Understanding the interplay between magnetic and optoelectronic propertiesand developing spin-optoelectronic devices are promising research strategiesto further study 2D materials and advance their applications. Here, thebroadband photoresponse in the newly synthesized magnetic Fe0.75Ta0.5S2single crystals is reported. Because the uncompensated magnetic moment ofthe spin glass state is pinned by the moment of the antiferromagnetic state,a large exchange bias field of ≈1.98 T is found at 2 K when cooled down at afield of 7 T. The as-prepared samples show a large negative magnetoresistance(nMR). The field dependence of nMRs displays a similar trend up to50 K, which is likely to originate from the significant dependence of the localizationlength on magnetic field. In addition, a photodetector prepared usingFe_(0.75)Ta_(0.5)S_2 flakes exhibits a fast response time (121.7 ms), good stability,high responsivity of 26.1 A W~(?1), and broadband photodetection, showingapplication potentials in spin-optoelectronics.