The temperature influence on the Cs/GaAs surface electronic properties, which determine the photon enhanced thermionic emission (PETE), is studied. It was found that heating to moderate temperatures of about 100 degrees C leads to substantial changes in the magnitude and shape of Cs coverage dependences of photoemission current and surface band bending, along with the changes of relaxation kinetics after Cs deposition. A spectral proof of the PETE process is obtained under thermal cycling of the Cs/GaAs surface with 0.45 monolayer (ML) of Cs. (C) 2016 Elsevier B.V. All rights reserved.