Evaluation of Mg₂Si TPV cells fabricated on n-Mg₂Si substrate by thermal diffusion of Ag acceptor

Abstract

We have successfully fabricated Mg2Si thermophotovoltaic (TPV) cells with a pn junction on an n-type Mg2Si substrate through a simple thermal diffusion process involving the diffusion of Ag as an acceptor impurity. The current-voltage characteristics of the cell were evaluated under irradiation of 1310 and 1550 nm laser diodes (LDs). The open-circuit voltage (VOC ) and short-circuit current (ISC ) were found to be 0.044 V and 1.2 mA, respectively, under irradiation with a 1310 nm-LD. The external quantum efficiency of the TPV cell was estimated to be approximately 24.3% based on the short-circuit current. A comparison of the simulation results with the experimental data indicates that the VOC and ISC of TPV cells can be markedly enhanced by minimizing the leakage current and surface recombination velocity.