Effect of the intrinsic layer thickness on the spectral performance of p-i-n structure 4H-SiC ultraviolet photodetector

The absorption coefficients of 4H-SiC at 200 – 400 nm were obtained by extrapolation and polynomial fitting methods. Considering the effect of different junction-depth on the spectral performance, the continuity equations of photo-generated minority carrier were used to theoretically calculate the responsivity of p⁺-n⁻(i)-n-n⁺ structure 4H-SiC ultraviolet photodetector (PD) and to find out the effect of the intrinsic layer thickness on the spectral performance. The theoretical analyses can be applied to the practical design of p-i-n structure 4H-SiC PDs.