Quality for sunny projects!
Mono - and polycrystalline silicon cells modules are the most common. Globally the most sold and used in both: small and large systems. Thin-film modules account for the remainder of the market.
It is crucial to understand the difference between cell, module and system efficiencies. The final performance will always be dependent on differences in radiation, available space, inclinations, climate, budget and many other specific conditions of each project.
Monocrystalline cells are more efficient than polycrystalline ones, and both are more efficient than thin-film cells. But thin-film modules can be considered efficient despite needing more surface for installation, because they use much less material than mono-and-polycrystalline silicon modules to be manufactured. They absorb light more effectively than crystalline, so the cell can be thinner. They are also very well adapted for cloudy, diffuse or indirect lighting conditions, inclination angles of less than 10° as well as for high temperatures. Different technologies have been developed within the thin-film modules. Some of the most relevant are:
- Amorphous silicon (a-Si) is a non-crystalline silicon that was the first thin-film material to yield a commercial product. Initially, a-Si was mostly used in consumer items such as calculators. Amorphous silicon is expanding its markets with its increasing efficiencies, proven manufacturability and innovative products (for example, modules that double as roof shingles or semitransparent modules for building-integrated uses).
- The microamorph silicon technology (a-Si/µc-Si) is a further development of amorphous thin-film cells in order to achieve a higher efficiency level. Those cells contain an additional, microcrystalline layer, which heightens the efficiency by up to ten percent.
- Copper indium selenium (CIS) cells offer high efficiency and excellent capacity even at low radiation. Introduced to the market with prototype modules reaching efficiencies greater than 12%. CIS is also enjoying success in the laboratory, with cell efficiencies climbing to a world-record 19.2%.
- Cadmium telluride (CdTe) is an excellent semiconductor for solar cells because its band-gap of 1.4 electron-volts is matched nearly perfectly to the solar spectrum. The device structure also includes a very thin layer of cadmium sulfide that allows most sunlight to pass through to the CdTe layer. These characteristics provide the potential for high-efficiency modules with low-cost manufacturing processes.
