Thin Films: Amorphous Silicon
These PV shingles are triple-junction amorphous silicon SHR-17 PV shingles from United Solar Systems Corporation. Each shingle produces 17 watts under full sun, for a total system size of 1.2kW. The shingles mount directly on to the roof structure and take the place of asphalt shingles.
Amorphous silicon (a-Si) 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).
Research on a-Si focuses on several of today's challenges:
-
Improving the stability and conversion efficiency of a-Si modules in actual use. In a detrimental phenomenon called the Staebler-Wronski effect, the conversion efficiency of a-Si module decreases when the module is first exposed to sunlight.
-
Reducing the capital equipment costs for manufacturing a-Si panels by improved manufacturing processes that include increasing the rates of depositing material.
-
Improving module-packaging designs to make them more resilient in outdoor environments and less susceptible to glass breakage or moisture ingress.
- Developing new module designs for building-integrated applications.