Comparative study of GaN betavoltaic battery based on p-n junction and Schottky barrier diode

This paper presents a theoretical calculation model of GaN betavoltaic battery with the Ni-63 radiation source. The output parameters of the GaN p-n junction battery and the GaN Schottky barrier battery are calculated based on Monte Carlo simulations. The calculation results show that when the thickness of (63)Nisource is 2 mu m , the GaN-Ni-63 batteries nearly achieve optimized performance. For the GaN-based p-n junction battery, the maximum output power density, filling factor, energy conversion efficiency and total energy conversion efficiency are 0.359 mu W/cm(2), 94.6%, 23.2% and 6.96%, respectively. For the GaN-based Schottky barrier battery, the output performance is related to the selection of the Schottky metal. Among the metals of Ag, Ti, Au, Pd, Ni and Pt for the GaN Schottky barrier diodes, the Au-GaN Schottky barrier device is typically fabricated. The corresponding output parameters of the Au-GaN Schottky barrier battery are 0.223 mu W/cm(2), 92.2%, 14.4% and 4.33%, respectively.