SEMICONDUCTOR ELECTRODES .18. LIQUID JUNCTION PHOTO-VOLTAIC CELLS BASED ON N-GAAS ELECTRODES AND ACETONITRILE SOLUTIONS

Regenerative photoelectrochemical cells (PEC) were constructed utilizing single crystal n-GaAs in acetonitrile solutions. Solution redox couples (an-thraquinone, p-benzoquinone, dimethyl ferrocene, ferrocene, hydroxymethyl ferrocene, and tetramethyl-p-phenylenediamine) whose standard redox potential varied by over 1.2V, were photooxidized at the semiconductor electrode and reduced at a Pt counterelectrode converting light directly into electrical energy. A power conversion efficiency of 14% was observed for the n-GaAs electrode in a ferrocene-ferricenium acetonitrile solution at a radiant intensity of 0.52 mW/cm2 of 720-800 nm light. The efficiency and stability were found to be very dependent upon the residual water concentration, radiant power, and concentration of electroactive species. © 1979, The Electrochemical Society, Inc. All rights reserved.