Examination of the effect of cell thickness on the performance of a tandem nano-gap thermophotovoltaic system

Abstract

In this paper, a study about the influence of cell thickness on the performance of a tandem thermophotovoltaic (TPV) system is performed in the near-field thermal radiation regime. This system includes an emitter made up of tungsten and two TPV cells made up of Si and GaSb, respectively. The fluctuational electrodynamics accompanied by the dyadic Green's function are applied in order to calculate the near-field thermal radiation heat flux. The generated photocurrent and the conversion efficiency are computed by solving the charge transport equations. By examination of the effect of TPV cell thicknesses on the performance of both cells, the optimum thicknesses are obtained. Furthermore, it is observed that variation of the n- or p-region thicknesses of the TPV cells also affect the performance of the system. In this regard, the best thickness for n- and p-regions of the first and second cells is also calculated.