Unidimensional photocurrent model for induced-junction photodiodes

At present, numerical simulations are the common method to predict the response of quantum efficient detectors based on induced-junction diodes. As alternative, this work proposes an analytical model based on photocurrent analysis where surface and bulk losses are modelled considering design and operation photodiode parameters and the characteristics of the incident beam. The model shows how, at short wavelengths, the surface recombination velocity dominates the losses that are directly proportional, whereas the bulk doping and reverse bias voltage determine the losses at long wavelengths. The results obtained by the here proposed analytical model are discussed for different values of surface recombination velocity and compared with simulations reported by other authors. For wavelengths from 400 nm up to 700 nm, the losses calculated by the analytical model at room temperature are in the order of tens of ppm for values between 1000 cm/s and 10000 cm/s of surface recombination velocity. Some simulations agree with a maximum difference of 80 ppm up to 700 nm, where the abrupt rise of bulk losses starts for the analytical model but it is shifted around 800 nm for reported simulations.