Pushing the Limits of Thermophotovoltaic Efficiency

We report power conversion efficiency of ~28% from a thermophotovoltaic device, employing the concept of photon regeneration. The regeneration is accomplished using photovoltaic band-edge as the spectral filter. This high efficiency is a direct consequence of enhanced sub-bandgap reflectivity of the device used. Our detail theoretical analysis shows that with further improvement in device geometry and material, it would be possible to achieve near 45% power conversion efficiency.