Visible blind p+-π-n--n+ ultraviolet photodetectors based on 4H-SiC homoepilayers

p–p–n –n ultraviolet photodetectors based on 4H–SiC homoepilayers have been presented. The growth of the 4H–SiC homoepilayers was carried out in a LPCVD system. The size of the active area of the photodetectors was 300 300mm. The dark and illuminated I–V characteristics had been measured at reverse biases form 0 to 20V at room temperature, and the illuminated current was at least two orders of magnitude than that of dark current below 13V bias. The peak value zones of the photoresponse were located at 280–310 nm at different reverse biases, and the peak value located at 300 nm was 100 times greater than the cut-off response value in 380 nm at a bias of 10V, which showed the device had good visible blind performance. A small red-shift about 5 nm on the peak responsivity occurred when reverse bias increased from 5 to 15V. r 2006 Elsevier Ltd. All rights reserved.