The Effect of Illumination Intensity on the Performance of Germanium Based-Thermophotovoltaic Cell

Abstract

The significance of optimizing power intensity in a thermophotovoltaic system had spurred the efforts on exploiting thermophotovoltaic cells which are typically installed near to the heat source. Germanium with 0.66 eV bandgap is recommended and extensively employed to harvest infrared radiation up to 1.8\ \boldsymbol{\mu} \mathbf{m}. The integration of this material contributes to a cost-effective thermophotovoltaic system by capturing long wavelength under low blackbody temperature. Contrarily, the atmospheric perturbation between the heat source and the germanium thermophotovoltaic cells affects the intensity of incoming illumination, which alters the electrical performance of the cells. Nonetheless, the investigation of this issue is remained at the infancy stage and more characterization works are required to understand the influence of illumination intensity on the cell conversion efficiency. In this work, Silvaco TCAD software was used to characterize single Ge thermophotovoltaic cell under 2000 K blackbody radiation temperature by manipulating the illumination intensity. A conversion efficiency of 11.8% was achieved under higher illumination intensity of 2000 K due to the increase in the maximum voltage from 0.19 V to 0.42 V when compared to AM 1.5 illumination condition. The success of this work will contribute to the incorporation of understanding the effect of incident illumination intensity on the performance of Ge cell. © 2019 IEEE.