Highly Sensitive Photodetectors Based on WS₂ Quantum Dots/GaAs Heterostructures

The performance of the photodetector is significantly impacted by the inherent surface faults in GaAs nanowires（NWs）. We combined three-dimensional（3D）gallium arsenide nanowires with zero-dimensional（0D）WS₂ quantum dot（QDs）materials in a simple and convenient way to form a heterogeneous structure. Various performance enhancements have been realized through the formation of type II energy bands in heterostructures，opening up new research directions for the future development of photodetector devices. This work successfully fabricated a high-sensitivity photodetector based on WS₂ QDs/GaAs NWs heterostructure. Under 660 nm laser excitation，the photodetector exhibits a responsivity of 368. 07 A/W，a detectivity of 2. 7×10¹² Jones，an external quantum efficiency of 6. 47×10²%，a low-noise equivalent power of 2. 27×10^-17 W·Hz^-1/2，a response time of 0. 3 s，and a recovery time of 2. 12 s. This study provides a new solution for the preparation of high-performance GaAs detectors and promotes the development of optoelectronic devices for GaAs NWs.