STRIKINGLY HIGH PHOTOVOLTAGES OF PHOTOELECTROCHEMICAL SOLAR CELLS EQUIPPED WITH PLATINUM-COATED AND ALKALI-ETCHED n-Si ELECTRODES

Abstract
Open-circuit photovoltages (Voc) of photoelectrochemical cells having an n-Si electrode coated with vacuum-evaporated platinum in an aqueous redox solution have been remarkably increased by etching the Pt-coated n-Si electrode in alkaline solutions. The maximum Voc obtained was 0.685 V, about 15% higher than that of normal p-n junction Si solar cells (0.59 V), demonstrating the possibility of using these cells as highly efficient solar energy converter. The large increase in Voc is explained by a theory recently proposed by us on semiconductor electrodes coated with microscopically discontinuous metal layers.