Thin-film solar panels are the second generation of solar panels, which are made by depositing one or more layers of photovoltaic photon absorbing materials on substrates such as glass, plastic or metal. Thin-film cells are very thin, typically ranging in thickness from a few nanometers to tens of microns, which makes thin-film solar cells both flexible and lightweight. Because of their high flexibility, thin-film cells can be used in building-integrated photovoltaics and semi-transparent photovoltaic glass materials.
There are four types of thin-film solar panels, including cadmium telluride (CdTe), copper indium gallium selenide (CIGS), amorphous silicon (a-Si), and gallium arsenide (GaAs).
Cadmium Telluride (CdTe)
CdTe is the most common thin-film solar technology, accounting for approximately 50% of the thin-film panel market. They are inexpensive to produce and install, CdTe panels can absorb light better than conventional panels, and modules have an average efficiency of 17% and a maximum of 22.1%.
Copper Indium Gallium Selenide (CIGS)
CIGS thin film cells use absorbers made of copper, indium, gallium, and selenium (CIGS) with laboratory efficiencies above 20%. They use less cadmium, which some companies use in place of zinc, making it an environmentally friendly option. However, these panels are very expensive, making it difficult to compete with traditional silicon or CdTe panels.
Amorphous Silicon (a-Si)
Amorphous silicon (a-Si) is an amorphous allotrope of silicon and is by far the most well-developed thin-film technology. Thin-film silicon is an alternative to traditional wafer (or bulk) crystalline silicon. They also last longer than CdTe and CIGS sheets, and they require far less silicon material than conventional panels. A-Si panels can bend, which makes them less prone to cracks.
Gallium Arsenide (GaAs)
Gallium arsenide (GaAs), a III-V direct bandgap semiconductor, is a very common material for single crystal thin film solar cells. GaAs solar cells have been one of the highest performing thin film solar cells due to their excellent thermal resistance and high efficiency. This is the best option if you want to improve your thin film solar efficiency. PV modules have a capacity of 28.8% but are also quite expensive.
Thin film solar panels include frameless solar cells. They are easy to manufacture, flexible and lightweight. Additionally, these panels are easier to install and the process takes less time. Can be adapted for Building Integrated Photovoltaics (BIPV), Roof and Marine applications, Portable applications, etc.
With further research and breakthroughs in thin-film solar cells, the technology can be adapted to more applications in the future and is likely to increase in market value not only in large-scale applications, but also in small commercial and residential areas in the next 10 years .