CHARACTERISTICS OF SEMICONDUCTOR PHOTODIODES IN THE VUV REGION

The responsivities as well as the losses of photons through reflection and absorption of a Si photodiode with a SiO2 film, and of a GaAs photodiode with a Au film are estimated using an optical model in the wavelength region from 9 to 800 nm. The model is compared with experiments performed in the visible-far ultraviolet region, and good agreements between the calculation and the experiments are obtained except for scale differences due to the surface recombination of carriers. It is shown that the rate of the surface recombination in a Si photodiode can be determined through a measurement of the internal quantum efficiency in the visible-far ultraviolet region. Thus, the spectral responsivities of semiconductor photodiodes in the VUV region can be roughly predicted. © 1990 IOP Publishing Ltd.