Spectral splitting thermophotovoltaic systems using GaSb and InGaAs cells

Abstract

Thermophotovoltaic (TPV) cells have garnered increasing attention due to their diverse range of potential applications. However, the efficiency of current TPV systems remains relatively low. It is widely recognized that a key solution to this issue lies in designing the radiation spectrum to match the spectral response of TPV cells. In this study, a novel approach is proposed to tune the spectrum of photons incident to the cells. By using a dichroic mirror, the photon flux is split into two spectral bands: high energy photons are directed onto 0.72eV-GaSb cells, while lower-energy photons are directed onto 0.59eV-InGaAs cells, which have a lower bandgap. The split-band TPV structure, based on broadband a selective emitter, is experimentally investigated. The experiments demonstrated that the spectrum-splitting system composed of these two cells, the peak power density improved by up to 59.6% at 1000°C source temperature, indicating that spectral splitting is an effective method to enhance the overall performance of TPV systems. Additionally, the design of a TPV prototype based on this spectrum-splitting system is proposed for further investigation.