Photovoltaics (PV) is the name given to the process and technology by which sunlight is converted to electricity. Solar cells are the common term used for the actual devices that convert sunlight into electrical energy. In a solar cell, absorbed light creates free charge carriers in the material that are collected at electrodes, resulting in an electric current. The more light that hits the cell, and the higher the efficiency of the solar cell in converting photons of light into electricity, the greater the output of power.
Classical solar cells are made of inorganic semiconductor materials like silicon. Currently this technology cannot compete with fossil fuels in the cost-for-energy production. A new and potentially less expensive solar cell technology can be achieved with organic semi-conducting materials, or "plastic solar cells." Due to their light weight and flexibility organic solar cells can be incorporated into many common products to charge batteries. For example, the U.S. Army is exploring the possibility of making tents from organic solar materials.
One of the critical areas of inefficiency with current plastic solar cells is the electron transfer from polymeric material to the electron acceptor. With the materials in use, only a fraction of the electron energy is captured because of the mismatch in energy levels between the polymer and the electron acceptor. Luna's approach to solving this problem is to use our patented TRIMETASPHERE® carbon nanomaterial technology to better match the energy levels between the two materials.
Organic solar cells are an experimental, low-cost, lightweight alternative to the silicon-based solar panels in wide use today. Significant improvements in performance are required before organic solar cells will be a commercial success. Luna's scientists have made a significant progress in using TRIMETASPHERE® nanomaterials to increase the efficiency of organic photovoltaic (OPV) materials by increasing the voltage produced. Our TRIMETASPHERE® derivatives show enhanced open circuit voltages over the standard C60 reference devices. Luna is collaborating with the Department of Energy's National Renewable Energy Laboratories (NREL), where our results have been confirmed. Although further improvements are necessary, we are encouraged by our progress and we believe we are on a path to reach higher efficiencies.
A good explanation about photovoltaic energy can be found at the Energy Information Association Web site.