Optimization of the Parameters of an Energy Converter Based on a Silicon p–i–n-Diode

To design photodetectors that convert radiation energy efficiently, a clear understanding is required of the relationship between the design features of the photodiode and the nature and parameters of the radiation that needs to be converted. In this study, the functional dependencies that allow optimizing the design parameters of a p–i–n-diode by relating the conversion coefficient of the recorded radiation fluxes into photocurrent with the design parameters of the photodetector and with the characteristics of the radiation source are presented. In the approximation of the predominance of ionization losses in the receiving region of the energy detector by beta electrons (Bethe, nonrelativistic case), expressions are obtained for calculating the optimal thicknesses of the receiving layers of the converters. Using the example of specific beta radiation sources, the efficiency coefficients of detectors for applications in beta-voltaic power supplies are determined and the dependencies of the efficiency coefficient on the energy of beta electrons and the width of the p–i–n-diode’s receiving region are plotted. The results obtained can be useful in the design of radiation converters and for assessing the efficiency of converters of the input cascades of real metrological devices.