Fabrication of highly lattice mismatched AlInSb diodes on GaAs substrates for thermophotovoltaic cells

Abstract

We have fabricated and investigated the optical properties of highly lattice mismatched AlInSb thermophotovoltaic cells grown on GaAs substrates. Defects, such as dislocations and surface damage, were minimized by controlling the strain of the film structure and by using a silicon nitride passivation layer. An output power density of 9.7 mW cm−2 was achieved under 1000 °C blackbody radiation with an incident power density of 1.63 W cm−2, which gave a power conversion efficiency of 0.59 %. Optimal efficiency of above 5% was estimated by a simulation using recombination parameters obtained from electroluminescence analysis. Additionally, a six-fold increase in spectral efficiency was confirmed by using a 3.3 μm monochromatic light source, which indicated that a thermophotovoltaic cell with a high efficiency of more than 30% would be possible in combination with wavelength-selective emitter.