May 08, 2017
A solar cell or photo voltaic cell is a device that converts light energy into electrical energy. A thin-film solar cell is a 2nd generation solar cell which is manufactured by depositing one or more thin film or thin layers of photovoltaic material on a substrate like plastic or glass or metal. The thickness of the films ranges between few nanometres to micrometres and hence much thinner than the conventional crystalline silicon solar cell whose thickness measures up to 200 micrometres. The thinness of these solar cells make them flexible and light weight and can be used as laminated glazing material on windows and hence serving a dual purpose. Also, the lab cell efficiency for CdTe and CIGS is more than 21 percent, hence better than multicrystalline silicon solar cells.
Different kinds of thin film solar cells that are commercially available are copper indium gallium diselenide (CIGS), cadmium telluride (CdTe), amorphous thin-film silicon (a-Si, TF-Si) etc. Cadmium Telluride (CdTe) is the most common and widely used solar cells having almost 50% of market share. However due to presence of significant amount of cadmium, it is highly toxic. Copper indium gallium diselenide (CIGS) solar cells have efficiency of 22.3%. The main manufacturer of CIGS cells was Solyndra, but since it went bankrupt in 2011, the leading manufacturer today is Solar Frontier. Gallium Arsenide (GaAs) solar cells are very expensive technology and has world record efficiency of 28.8%.GaAs is mainly used on spacecrafts and for versatile, mass-scale instalments of PV energy. Amorphous Silicon (a-Si) solar cells have a technology similar to a standard silicon wafer panel. a-Si is a much better option than its CdTe and CIGS because of its lesser toxicity and more durability. However it is less efficient and used for small loads like consumer electronics.
Other thin-film technologies which are under research and development include third generation photovoltaic cells, polymer solar cells, perovskite solar cells, quantum dot, copper zinc tin sulfide, nanocrystal, micromorph, organic, dye-sensitized solar cells.