Designing a Heterojunction N+ on P GaSb Thermophotovoltaic Cell with hydrogenated Amorphous Silicon Interface Passivation

An optimized design of a Heterojunction N+ on P GaSb thermophotovoltaic (TPV) cell with hydrogenated amorphous silicon interface passivation is presented. The N+ layer is a transparent conductive oxide (TCO). The interface recombination rate between the p-GaSb and a-Si:H(i) layers is found to have an important effect on cell performance. If this recombination rate can be reduced to 105cm/s, the internal quantum efficiency in the wave range of 600 1700 nm surpasses 95% and the output power density reaches 2W/cm2 under a given blackbody radiation of 1500K. The high minority carrier electron mobility and diffusion length in the p-GaSb leads to the high internal quantum efficiency. A potential advantage of this cell is its simple cell fabrication process for low cost in high volume manufacturing. Another advantage for this cell for TPV systems is a built in short pass plasma filter with a high reflectivity at longer wavelengths.