A comparatively experimental study on the temperature-dependent performance of thermophotovoltaic cells

The power output and the efficiency of a thermophotovoltaic (TPV) system are determined by the radiation from a heat source, TPV cells, system parasitic losses, cell cooling subsystems, etc. The cells are core devices of a system, and the performance of the cells can be characterized by a number of parameters, including open circuit voltage (V-oc), short circuit current density (I-sc), and maximum output power density (P-m). The cell temperature has a great effect on these parameters. Although several papers have reported the dependence of these parameters on the cell temperature, few studies experimentally examined the temperature-dependent performance of the TPV cells or comparatively analyzed them. In this study, we investigated how the fundamental parameters of GaSb, Ge, and InGaAsSb cells varied with their operating temperatures using a home-built TPV prototype. The measured data indicate that the cell temperature significantly affects the performance of the TPV cells. Variations of these parameters with the cell temperature are different for various TPV cells. The V-oc and P-m of the GaSb, Ge, and InGaAsSb cells decreased linearly with increasing cell temperature, while the I-sc increased slightly. The normalized value of the temperature coefficient for the P-m of the GaSb was lower than those for the Ge and InGaAsSb cells, which indicated that the GaSb cells were relatively less sensitive to cell temperature. The results provided in this study are useful to improve cell performance and design TPV systems.