Facile integration of an Al-rich Al1-xInxN photodetector on free-standing GaN by radio-frequency magnetron sputtering

Al1-xInxN,a Ⅲ-nitride semiconductor material,is currently of great research interest due to its remarkable physical properties and chemical stability.When the Al and In compositions are tuned,its band-gap energy varies from 0.7 eV to 6.2 eV,which shows great potential for application in photodetectors.Here,we report the fabrication and performance evaluation of integrated Al1-xInxN on a free-standing GaN substrate through direct radio-frequency magnetron sputtering.The optical properties ofAl1-xInxN will be enhanced by the polarization effect of a heterostructure composed ofAl1-xInxN and other Ⅲ-nitride materials.An Al1-xInxN/GaN visible-light photodetector was prepared by semiconductor fabrication technologies such as lithography and metal deposition.The highest photoresponsivity achieved was 1.52 A·W-1 under 365 nm wavelength illumination and the photodetector was determined to have the composition Al0.75In0.25N/GaN.A rise time of 0.55 s was observed after transient analysis of the device.The prepared Al1-xInxN visible-light photodetector had a low dark current,high photoresponsivity and fast response speed.By promoting a low-cost,simple fabrication method,this study expands the application of ternary alloy Al1-xInxN visible-light photodetectors in optical communication.