The efficiency and stability of a CdTe photoelectrochem. cell are increased by dipping n-CdTe single crystal photoelectrodes in H2PtCl6 or RuCl3 solution Besides the type of metal ions, the electrode pretreatment and dipping time have strong effects on modification. The solid surface analyses show that there are a large no. of Pt islands on the surface of electrodes dipped in PtCl62- solution for a short time which decrease the no. of defects and catalyze interfacial reactions. Dipping the electrode in RuCl3 solution will probably cause Ru3+ ions to be adsorbed on its surface, which is beneficial to the photoelectrochem. reaction. The electrodes treated with PdCl2 solution or dipped in H2PtCl6 solution for a long time give inferior results.

Key words: CATALYSIS, MODIFICATION, SINGLE CRYSTALS, IONS, PHOTOELECTROCHEMICAL EFFECT, CADMIUM TELLURIDE, PHOTOCHEMICAL CELLS, PHOTOELECTRIC MATERIAL