Study On The High-performance And Air-stable Near-infrared Photodetector Based On PdSe₂/GaAs Heterojunction

Photodetector is optoelectronic device that convert light signal into electrical signal,and has very important applications in modern science and real industry.Especially near-infrared photodetector with broad applications in military and civilian fields?night vision,target detection,video and biological imaging?,which has received enough attention in recent decades.After decades of continuous exploration and development by scientists,in order to make up for the short cut-off wavelength of commercial Si-based near-infrared photodetector,near-infrared photodetector based on materials such as In Ga As and related heterostructures have strict manufacturing conditions and complex manufacturing processes.Recently,a heterojunction near-infrared photodetector based on a 2D layered material and a narrow band gap semiconductor has been proposed,which has the outstanding characteristics of simple manufacture,low cost and high efficiency.In this work,we have studied a near-infrared photodetector based on Pd Se₂/Ga As heterojunction and measured excellent electrical performance.In this thesis,we prepared a multilayer Pd Se₂film by a simple one-step direct selenization method.The as prepared Pd Se₂/Ga As heterojunction device shows obvious photovoltaic characteristics under 808 nm near-infrared light,indicating that our device can work without external power.Further device performance analysis shows that the prefabricated heterojunction device is extremely sensitive to near-infrared light at 808nm.The photoresponse has good stability and repeatability,and the excellent stability is inseparable from the good stability of Pd Se₂.Besides,the Pd Se₂/Ga As heterojunction exhibits a large I_light/I_darkratio of 1.16×10⁵,a higher responsivity of 171.34 m A W^-1,and an excellent specific detectivity of 2.36×10¹¹Jones,under 808 nm light.Finally,the research found that the device can also be used as a near-infrared light sensor.The above research results indicate that the Pd Se₂/Ga As heterojunction has broad application prospects in the future photoelectric system.