South Korean scientists have developed a magical looking thin film solar panel with slight fluorescent colors that not only possesses a remarkable appearance, but is also produced with materials that are friendly to the environment, and the solar panel is able to achieve a conversion efficiency of 18% alongside its flexible and bendable advantages.
Most solar panels are navy blue crystalline solar cells. The cost of solar power has been decreasing with the increasing number of installed capacity each year and the maturity in the relevant technology in recent years, and the competitiveness of solar power is already on par with traditional coal-fired power generation even without subsidy. As pointed out by the International Renewable Energy Agency (IRENA), the cost of solar power is expected to reduce to US$0.039/kWh (approx. TWD$1.17) in 2021, which is a 42% reduction compared to 2019.
It is because of the crystalline solar cells that the prices of renewable energy are able to compete with traditional electricity, though it is rather difficult to install these “thick, rigid, and heavy” crystalline solar panels on rooftops, external walls, or high platforms, and they are also unable to integrate with clothes and small equipment.
Hence, the development of flexible solar technology would need to find another path, among which, perovskite solar, thin film solar, and organic solar, may be the potential solutions, where the Electronics and Telecommunications Research Institute of South Korea has recently succeeded in developing an eco-friendly thin film solar cell.
Thin film solar cell requires less materials than crystalline solar cells and relatively lower cost, and is able to adopt various materials, including glass, plastic, and ceramic, as the base plate, in terms of the production process, which creates diversity in the design of back-end solar panels. The commonly seen technologies in thin film solar cells are CIS and CIGS, and the conversion efficiency is only second to that of crystalline solar cells.
Why is this new solar panel from South Korea regarded as “eco-friendly”? Although thin film solar panels from the past consisted of advantages in flexibility and low cost, the toxic heavy metal cadmium in the buffer layer between the transparent conducting layer and the absorption layer makes it difficult for promoting the thin film solar panels. Hence, ETRI scientists have replaced cadmium with cadmium sulfide (CdS), which reduces the concern on environmental pollution, and creates thinner solar cells through the use of zinc.
ETRI studies zinc-based buffer layer solar cells through photo-pumping terahertz spectroscopy, and it is hoped that the particular study provides the foundation for the next generation eco-friendly solar power. As commented by ETRI chief researcher Yong-Duck Chung, this study will help solar power march towards colorful solar modules of high added economic values.
Thin film solar cells are currently at 3µm in thickness, with a conversion efficiency of 18%, which has surpassed the commercialization standard of 15%. Furthermore, in order to provide additional competitiveness, ETRI scientists have also developed 7 lustrous thin film solar panels, including pink, yellow, purple, green, and blue that are quite remarkable and attractive compared to the monotonous navy blue of crystalline solar panels.
(Cover photo source: ETRI)