Around the world, research on solar cells to harness renewable energy sources is going on. In one such effort, the Electronics and Telecommunications Research Institute at South Korea has succeeded in developing eco-friendly, thin-film, and color CIGS solar cells.
CIGS thin-film solar cells find use to convert sunlight into electrical energy and are synthesized by coating multiple thin films on a glass substrate. Among a range of non-silicon based cells, the films have a relatively higher absorption coefficient that results in high conversion efficiency and long stability. Also, these films require less raw material than what is required by silicon-based ones; hence, small process and material costs.
Nonetheless, difficulty in commercialization has been a downside of solar films as have a buffer layer containing cadmium – a toxic heavy metal. For this, the research team replaced cadmium sulfide buffer layers with zinc-based materials. These materials are not harmful and achieved a conversion efficiency of almost 18%, thus eliminating a hurdle to commercialization.
Technology close to full-on Commercialization
Likewise, the technology is one step closer to commercialization for another factor. Availability of more than seven colors including green, purple, green, and blue which does not require additional process or cost. Moreover, the researchers succeeded to identify a new analysis method that uses photo-pumping terahertz spectroscopy and a mechanism to improve the conversion efficiency of solar cells with zinc-based buffer layers. Being thin, the solar cells can be coated on both a flexible substrate and glass substrate. This implies, the thin solar cells could be bent or folded, expanding their applications as a next-generation eco-friendly source of energy.
With thin-film solar cells, it will contribute to the development of solar power system through the production of color high value-added photovoltaic modules.