PEC Cells

Efficiency levels relatively low (14~252) compared to efficiency levels of other renewable energy systems PEC Cells Photocument generated device made up of an electrocyte cy a photoactive semiconductor electiode Device in which a photoactive semic. material is in contact with electrolyte. Irradiation of S&/ electrolyte junction with bright of energy 7 Eg, band gap of SC / produces e-hole pairs. e-holepairs are spatially seperated Caue to jct. potential) to drive oxidation Cy reduction reactions in the system. Types 1. Liquid Jet SC n SC /Electrolyte/Metal G Free is in SC absorb the high energy radiation Cy then the excited is will more from the valence band to conduction band of SC. As a result, holes are created Used to convert solar elictrical

2. PES - solarEto chemical in form of fuels Advantages of PEC over PV. Gasy jct formation (mere dipping of 8C electr ode in electrolyte). In-situ water electrolysis possible Efficiencies of poly crystalline bulkly thin film electrodes are comparable to thox of single crystal electrodes effects Novel (plato rxn catalysis) can be induced on SC surfaces products are possible by catalytic Particulate systems can be used Conditions for Efficient solar Energy Conversion-Entrode 1. Band gap (Eg) should be optimum there 2. Doping level should be optimum ,so that the photo will be a good spatial seperation of efficiency 3. should have large values of absorption afficient( SC's. generated carriers and hence, high quantime effect 4. Applied bias (external energy source makes the LJSCs more efficient this is usually found for direct band gap