Improved performance of a near-field thermophotovoltaic device by a back gapped reflector

Various spectral control techniques can be applied to improve the performance of a thermophotovoltaic (TPV) device. For example, back surface reflector (BSR) is common structure TPV devices. A conventional metal BSR enhances photogeneration rate by increasing absorption probability photons via reflections, affording second chance for absorption. However, effects passivation and external luminescence introduced structures have been previously ignored, which potentially decreases Recently, gapped (BGR) was proposed greatly far-field devices reducing imperfect reflections at semiconductor-metal interface. In present work, improvement on thin-film, near-field InAs device with BGR investigated, comparing its that BSR. Surface conditions are also investigated further reflectors. The output power efficiency calculated using an iterative model combining fluctuational electrodynamics full drift-diffusion model. well-passivated condition, when replaced BGR, conversion improved from 16.4% 21% increased 10%. Finally, reflectors loss analyzed explain improvement.