CURRENT PHOTORESPONSE OF AN ELECTROLYTE-ZINC SELENIDE JUNCTION

Photocurrents obtained by excitation of an electrolyte–zinc selenide junction with the aid of photons whose energy is lower than the semiconductor band gap (2.7 eV) are analyzed. It is possible to explain the shape of the experimentally obtained photoresponses by transfer of photoexcited electrons from the valence band to energy levels located below the conduction band, followed by another transfer from this level to the conduction band. The last effect can be expressed by a Poole‐Frenkel mechanism for the deeper level, tunnelling accounting for the response (current) obtained with electrons photoexcited closer of the conduction band. In each case, the flat band potential value is determined and compared with results obtained by impedance measurement. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA