Thermally enhanced photoelectric emission from GaAs photocathode

Thermally enhanced photoelectric emission (TEPE) is a method for solar energy conversion, and it combines the quantum approach and the thermal approach. Different from photon-enhanced thermionic emission (PETE), TEPE is based on the photoelectric emission model rather than the thermionic emission model. In this paper, numerical calculations for the conversion is proposed under detailed balance condition. By using a double dipole layer surface model, the theoretical conversion efficiency of TEPE conversion from a GaAs photodiode is calculated. The emission current of TEPE increases with the temperature until all the excited electrons are emitted. An experimental setup with a NEA GaAs vacuum photodiode was applied. Assuming a phosphorus-doped diamond film with a work function of 0.9 eV as the anode, the energy conversion efficiency can be estimated, and it increases from 4.92% to 5.11% as the temperature rises from 20 °C to 80 °C.