EFFECTS OF CATIONS ON THE PERFORMANCE OF THE PHOTOANODE IN THE N-GAAS-K2SE-K2SE2-KOH-C SEMICONDUCTOR LIQUID JUNCTION SOLAR-CELL

Cations adsorbed on n-GaAs affect the fill factor and the open-circuit voltage of the n-GaAs |0.8M K2Se-0.1M K2Se2-1M KOH|C cell. An AMI solar-to-electrical conversion efficiency of 12% is reached by chemisorbing Ru(III) on the photoanode. This efficiency is maintained upon passage of 35,000 C/cm2. The effect of Ru(III) is interpreted as a reaction with a surface chemical entity associated with a surface state near the conduction band, which shunts the cell by allowing electrons to tunnel through the barrier at the junction. Reaction with Ru(III) converts the shunting surface state to one to which electrons cannot tunnel. Being strongly adsorbed, Ru(III) also reduces the effect of certain impurities such as Bi (III) which otherwise decrease the power output. © 1979, The Electrochemical Society, Inc. All rights reserved.