Effect of Si Doping on the Performance of GaN Schottky Barrier Ultraviolet Photodetector Grown on Si Substrate

GaN Schottky barrier ultraviolet photodetectors with unintentionally doped and lightly Si-doped n−-GaN absorption layers were successfully fabricated, respectively. The high-quality films on the Si substrate both have a fairly low dislocation density point defect concentration. More importantly, effect of doping performance GaN-on-Si photodetector was studied. It found that light in layer can significantly increase responsivity under reverse bias, which might be attributed to persistent photoconductivity originates from lowering height. In addition, devices demonstrated relatively high-speed photo response. We briefly studied mechanism changes barrier, dark current characteristic response time.