The National Renewable Energy Laboratory (NREL) classifies a number of thin-film technologies as emerging photovoltaics—most of them have not yet been commercially applied and are still in the research or development phase. Many use organic materials, often organometallic compounds as well as inorganic substances. Despite the fact that their efficiencies had been low and the stability of the absorber material was often too short for commercial applications, there is a lot of research invested into these technologies as they promise to achieve the goal of producing low-cost, high-efficient solar cells.
Emerging photovoltaics, often called third generation photovoltaic cells, include:
- Copper zinc tin sulfide solar cell (CZTS), and derivates CZTSe and CZTSSe
- Dye-sensitized solar cell, also known as “Grätzel cell”
- Organic solar cell
- Perovskite solar cell
- Polymer solar cell
- Quantum dot solar cell
Especially the achievements in the research of perovskite cells have received tremendous attention in the public, as their research efficiencies recently soared above 20 percent. They also offer a wide spectrum of low-cost applications. In addition, another emerging technology, concentrator photovoltaics (CPV), uses high-efficient, multi-junction solar cells in combination with optical lenses and a tracking system.