
In addition to the direct photovoltaic excitation of free electrons, an electric current can also arise through the . When a conductive or semiconductive material is heated by absorption of electromagnetic radiation, the heating can lead to increased temperature gradients in the semiconductor material or differentials between materials. These thermal differences in turn may generate a voltage because the electron energy levels are shifted differently in different are.

Environmental issues, effects, impacts, and benefits of solar energy production and use. . Solar Energy Basics U.S. Department of Energy Solar Energy Technologies Office Solar Photovoltaic Module Recycling: A Survey of U.S. Policies and Initiatives End. . Energy and the environment Electricity and the environment