Résumé
Thermophotovoltaic (TPV) systems propose a promising method of converting heat into electricity, with the thermal emitter playing a pivotal role. However, optimizing its emission spectrum poses a significant challenge, with sub-bandgap losses and thermalization from high-energy photon absorption contributing to this complexity. Although the absorption of high-energy photons is beneficial for increasing the system’s power output by providing additional energy, it simultaneously diminishes the system’s efficiency. This study addresses these challenges by exploring the optimization of the emission spectrum of selective thermal emitters in TPV systems. Our objective is to reach a balance between maximizing electrical power output, which favors a broadband spectrum, and maximizing efficiency, which requires a narrowband spectrum. To achieve this, numerical optimization methods are coupled with the Shockley-Queisser limit to find an optimal compromise between these opposing criteria. Ultimately, this optimization endeavor aims to enhance the overall performance of TPV systems. Here, we present the results of calculations predicting the spectral shapes of ideal selective emitters for TPVsystems with emitter temperatures ranging from 300◦C to 2000◦C and photovoltaic cell bandgap energies from 0.17 eV to 1.1 eV. For a configuration with an emitter at 900◦C coupled to a 0.25 eV bandgap cell under the assumption of perfect coupling (view factor of 1), the ideal emission spectrum was found to have emissivity of unity between 0.25 eV and 0.62 eV and zero elsewhere. Accounting for this ideal emission spectrum, the results show an efficiency of 41.5% and an output power density of 2.59 W∕cm2.