Solar cells can be classified as:
- Mono crystalline solar cell
- Poly crystalline solar cell
- Thin film solar cell
Mono Crystalline solar cells are produced by wafers of highly pure single Si crystal. Metallurgical grade silicon is purified to form semiconductor grade silicon. Mono crystalline solar cells have highest efficiency of around 20%. Due to the high efficiency, mono crystalline cell require less space to generate more power. The cost of Mono crystalline cells is very high compared to other technologies. Mono crystalline cells are highly vulnerable to temperature effects. This technology is well developed and gives a stable power output. Mono crystalline cells have less power degradation over time when compared to other technologies.
Poly crystalline solar cells are produced from various small crystals pieced together. Poly crystalline solar cells have an efficiency of around 16%. The cost of poly crystalline cells is apparently less than mono crystalline solar cells. The technology is well developed and is being mostly used in the solar pv market today. Poly crystalline cells are easily available in the market. They require less space to generate more power. Poly crystalline cells experiences high impact of temperature variations. Poly crystalline cells have high power stability.
Thin film solar cells use have increased in India drastically in last two three years. In thin film technology, very thin layers of semiconductor material are deposited on to either coated glass or stainless steel or a polymer. Thin film cell is the cheapest cell technology when compared to mono and poly crystalline cell technologies. Thin film cells however have less efficiency of around 12%. This type of solar cell requires more area to produce same power as by mono / poly crystalline solar cells. Thin film solar cells face lesser impact of temperature variation. Thin film solar cell has little higher degradation of power, when compared to other technologies. There is no requirement of cooling, since they have less effect of temperature variations.