Preliminary results of an analytical model to determine the internal quantum efficiency of a predictable quantum efficient detector

Abstract

The potential of predictable quantum efficient detectors (PQEDs) as optical radiant power primary standard, based on photoelectric effect in silicon semiconductor, has been proved. Until now, the internal quantum efficiency (IQE) of a PQED is only predicted, from the design and setup parameters of the two photodiodes of this radiometer, by means of simulation software for semiconductor devices. This work presents, as alternative method, an analytical model based on Ferrero et al. photocurrent analysis, which considers the different internal regions of the photodiode and the characteristics of the incident beam. The IQE grows with the reverse bias voltage applied to the photodiodes and the lifetime of the charge carriers in the bulk, while IQE decreases when the surface recombination velocity and the doping concentration of the substrate are increased. The IQE results of the analytical model are similar to simulations for wavelengths between 400 nm and 700 nm. Moreover, the analytical model predicts an increase of the IQE with the irradiance, at certain levels of optical power due to the supra-responsivity of the photodiode.