Raising the Temperature: Comparing HgCdTe and III-V Thermoradiative Diodes

The thermoradiative diode (TRD) is the symmetric counterpart to the photovoltaic solar cell that generates power via the net emission rather than absorption of light. While the theoretical limits for power generation are promising in the radiative limit, current experimental demonstrations remain far from that limit. Here compare the optoelectronic characteristics of both HgCdTe and III-V photodiodes operating in both thermoradiative and thermophotovoltaic modes with nominal bandgaps ranging from 4μm to 10.6μm, supported by optical modelling. We conclude that for moderate temperatures and bandgaps HgCdTe diodes outperform III-V diodes, but only III-V devices can operate at the elevated temperatures that may be required for some applications. The thermoradiative diode (TRD) is the symmetric counterpart to the photovoltaic solar cell that generates power via the net emission rather than absorption of light. While the theoretical limits for power generation are promising in the radiative limit, current experimental demonstrations remain far from that limit. Here compare the optoelectronic characteristics of both HgCdTe and III-V photodiodes operating in both thermoradiative and thermophotovoltaic modes with nominal bandgaps ranging from 4μm to 10.6μm, supported by optical modelling. We conclude that for moderate temperatures and bandgaps HgCdTe diodes outperform III-V diodes, but only III-V devices can operate at the elevated temperatures that may be required for some applications.