Micron-sized liquid nitrogen-cooled indium antimonide photovoltaic cell for near-field thermophotovoltaics

Abstract

Simulations of near-field thermophotovoltaic devices predict promising performance, but experimental observations remain challenging.Having the lowest bandgap among III-V semiconductors, indium antimonide (InSb) is an attractive choice for the photovoltaic cell, provided it is cooled to a low temperature, typically around 77 K. Here, by taking into account fabrication and operating constraints, radiation transfer and low-injection charge transport simulations are made to find the optimum architecture for the photovoltaic cell.Appropriate optical and electrical properties of indium antimonide are used.In particular, impact of the Moss-Burstein effects on the interband absorption coefficient of n-type degenerate layers, and of parasitic sub-bandgap absorption by the free carriers and phonons are accounted for.Micron-sized cells are required to minimize the huge issue of the lateral series resistance losses.The proposed methodology is presumably relevant for making realistic designs of near-field thermophotovoltaic devices based on low-bandgap III-V semiconductors.