<P> A new attempt to fuse the advantages of bulk silicon with those of thin - film devices is thin film polycrystalline silicon on glass . These modules are produced by depositing an antireflection coating and doped silicon onto textured glass substrates using plasma - enhanced chemical vapor deposition (PECVD). The texture in the glass enhances the efficiency of the cell by approximately 3% by reducing the amount of incident light reflecting from the solar cell and trapping light inside the solar cell . The silicon film is crystallized by an annealing step, temperatures of 400--600 Celsius, resulting in polycrystalline silicon . </P> <P> These new devices show energy conversion efficiencies of 8% and high manufacturing yields of> 90% . Crystalline silicon on glass (CSG), where the polycrystalline silicon is 1--2 micrometres, is noted for its stability and durability; the use of thin film techniques also contributes to a cost savings over bulk photovoltaics . These modules do not require the presence of a transparent conducting oxide layer . This simplifies the production process twofold; not only can this step be skipped, but the absence of this layer makes the process of constructing a contact scheme much simpler . Both of these simplifications further reduce the cost of production . Despite the numerous advantages over alternative design, production cost estimations on a per unit area basis show that these devices are comparable in cost to single - junction amorphous thin film cells . </P> <P> The semiconductor material gallium arsenide (GaAs) is also used for single - crystalline thin film solar cells . Although GaAs cells are very expensive, they hold the world record for the highest - efficiency, single - junction solar cell at 28.8% . GaAs is more commonly used in multi-junction solar cells for solar panels on spacecrafts, as the industry favours efficiency over cost for space - based solar power (InGaP / (In) GaAs / Ge cells). They are also used in concentrator photovoltaics, an emerging technology best suited for locations that receive much sunlight, using lenses to focus sunlight on a much smaller, thus less expensive GaAs concentrator solar cell . </P> <P> 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 . </P>

Thin-film amorphous silicon solar panels (a-si)