Spectral quantum efficiencies of semiconductor photodiodes in the far ultraviolet region

Abstract

The spectral quantum efficiencies and reflectances of p-i-n-type Si photodiodes and a Schottky-type GaAsP photodiode were measured in the wavelength region between 105 to 300 nm. These results are compared with an optical model using complex refractive indices. The spectral relative external quantum efficiencies are well interpreted within the model by assuming that the production energy of an electron-hole pair, ε, is wavelength independent. It is suggested that surface recombination of minority carriers occurs in some devices. The internal quantum efficiency for the GaAsP photodiode is shown to be constant in the photon energy range below about 5.4 eV. The recombination loss and the ε value are separately estimated.