Thermal radiation-matter interaction analysis and optimal design of InAs-based intermediate-band thermophotovoltaic cells

This study presents a framework for optimizing InAs-based intermediate-band thermophotovoltaic cells (IB-TPVCs) by enabling sub-bandgap photon absorption and carrier excitation. The transfer matrix method, integrated with the Drude–Lorentz model, is developed to quantify the angle- and wavelength-dependent absorptivity of multilayer structures for both transverse electric (TE) and transverse magnetic (TM) modes. The absorption spectra for TE mode exhibits distinct oscillatory peaks and valleys, which are caused by optical properties, structural parameters, interference, and resonance effects. The TM mode achieves stronger absorption at specific wavelengths and angles due to surface plasmon resonance and enhanced optical coupling. The spectral photon fluxes are calculated by combining the layer absorptivity with the blackbody radiation spectrum given by Planck's law. Furthermore, the internal quantum efficiency is examined as a function of both the absorber thickness and the photon wavelength. Based on these spectral and efficiency parameters, the short-circuit current density spectrum is calculated. The net current density is then determined by accounting for radiative, non-radiative, and dark current losses. Local optimization is performed by tuning the doping concentration under fixed structural and temperature conditions, while global strategies for maximizing power density and efficiency offer key insights for advancing TPV technology.