When a solar panel is exposed to sunlight, electrons (negative) and holes (positive) are generated. The basic operating principle and structure of solar cells, as well as typical materials and power conversion efficiencies of silicon and compound semiconductor solar cells, are explained below. A: Anti-reflection film B: n-type silicon C: p-type silicon D: Electrodes E: Current Silicon solar. Solar cells, or photovoltaic cells, are the foundation of modern solar energy technology. This. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness.