Photochemical Conversion of Solar Energy into Electrical Energy in an Eosin–Mannose System

Abstract

Solar energy has been converted into electrical energy using an eosin-mannose system in a photogalvanic cell. The system uses solutions of sufficiently low concentration to be commercially viable. The photopotential and photocurrent generated by the system were 758.0 mV and 170.0 µA, respectively, while the maximum power and power point were 128.86 and 67.20 µW, respectively. The observed conversion efficiency was 0.6461% and the fill factor was 0.3739 against an absolute value of 1.0. The developed photogalvanic cell can operate for 75 min in the dark following irradiation for 120 min, i.e., the observed storage capacity is 62.5%. A mechanism for the photogeneration of electricity in the system has also been proposed. The developed photogalvanic cell exhibits appreciable conversion efficiency and storage capacity of solar energy, which along with its inexpensive construction make it promising for solar cell applications.