Computational study of III-V direct-gap semiconductors for thermoradiative cell applications

We investigate the performance of thermoradiative (TR) cells using the III-V group of semiconductors, which include GaAs, GaSb, InAs, and InP, with the aim of determining their efficiency and finding the best TR cell materials among the III-V group. The TR cells generate electricity from thermal radiation, and their efficiency is influenced by several factors such as the bandgap, temperature difference, and absorption spectrum. To create a realistic model, we incorporate sub-bandgap and heat losses in our calculations and utilize density-functional theory to determine the energy gap and optical properties of each material. Our findings suggest that the absorptivity of the material, especially when the sub-bandgap and heat losses are considered, can decrease the efficiency of TR cells. However, careful treatment of the absorptivity indicates that not all materials have the same trend of decrease in the TR cell efficiency when taking the loss mechanisms into account. We observe that GaSb exhibits the highest power density, while InP demonstrates the lowest one. Moreover, GaAs and InP exhibit relatively high efficiency without the sub-bandgap and heat losses, whereas InAs display lower efficiency without considering the losses, yet exhibit higher resistance to sub-bandgap and heat losses compared to the other materials, thus effectively becoming the best TR cell material in the III-V group of semiconductors.

Automated summary

In this study, we evaluated the performance of thermoradiative (TR) cells using III-V group semiconductors and aimed to identify the most efficient TR cell material among GaAs, GaSb, InAs, and InP. The efficiency of TR cells, which convert thermal radiation into electricity, is affected by factors such as bandgap, temperature difference, and absorption spectrum. To create an accurate model, we considered sub-bandgap and heat losses and employed density-functional theory to determine the energy gap and optical properties of each material. Our findings indicate that the absorptivity of the material can decrease the efficiency of TR cells, especially when considering sub-bandgap and heat losses. However, the effect of absorptivity on TR cell efficiency varies among different materials. GaSb exhibited the highest power density, while InP demonstrated the lowest. GaAs and InP showed relatively high efficiency without sub-bandgap and heat losses. InAs had lower efficiency when not considering losses but displayed higher resistance to sub-bandgap and heat losses compared to other materials, making it the best TR cell material among the III-V group of semiconductors.