Output Power Density of Intermediate-Band Thermoradiative Diodes with Doping-Concentration Limits |
Yukihiro Harada, Fuka Nishii, Takashi Kita Kobe University, Kobe, --, Japan |
We studied the output power density of the thermoradiative diode (TRD) with an intermediate band (IB) in the detailed balance framework. The output power density of the IB-TRDs increases at higher device temperatures and the optimal position of the IB leaves the middle of the bandgap of the host semiconductor when the bandgap energy is larger than 0.5 eV resulting from the current matching constraint. As the intrinsic carrier density must be sufficiently lower than the doping concentration to form a p–n junction at the operating temperature, the IB-TRDs have an advantage compared with the single-junction TRDs consisting of narrow-bandgap semiconductors. An output power-density limit of ≈ 17 W/m2 is estimated for GaAs-based IB-TRDs with an intrinsic carrier density of 1015 cm−3 at a device temperature of 760 K and an environment temperature of 300 K. |