GaAs film for photon-enhanced thermionic emission solar harvesters

Abstract A novel concept for solar electricity generation named photon-enhanced thermionic emission (PETE) was recently proposed for harvesting solar photonic and thermionic energies simultaneously. Comparative investigations showed that the conversion efficiency of PETE can theoretically exceed 40%. In this paper, an electric field-assisted PETE experiment was carried out to demonstrate the possibility of using GaAs epitaxial films in PETE solar devices. The solar photonic and thermionic effects were simulated by a red light-emitting diode array and a heat resistor, respectively. Surface electron affinity was decreased by an electric field instead of Cs/Cs–O coating. The experimental results agreed with calculated values, and a distinct enhancement was observed in the thermionic emission produced by photoexcitation compared with thermionic field emission produced by an illuminated sample and the sample emission obtained in the dark.