A Company in Japan Just Broke the World Record for Solar Panel Efficiency

Solar Energy / Resource Evaluation

Date posted: 04/02/17

Patrick Caughill reports that the use of solar power is on the rise around the world. There are massive solar power generating installations across Asia, with countries like India and China taking turns being the home of the largest arrays. Even the U.S. is making some massive strides with this source of renewable energy. In fact, solar energy is faring better than coal, even in terms of the economy. There are more people employed by the solar industry than in coal, and the price of solar power continues to fall. A trend that is likely to continue, especially if we continue to improve the efficiency of PV cells. To that end, researchers in Japan are doing their part ... a team from the company Kaneko has recently announced breaking the efficiency record of solar panels, which now stands at 26.6%. Improving the photoconversion efficiency of silicon solar cells is crucial to further the deployment of renewable electricity, says the team. Yoshikawa, et.al., indicate that essential device properties such as lifetime, series resistance and optical properties must be improved simultaneously to reduce recombination, resistive and optical losses. Here, we use industrially compatible processes to fabricate large-area silicon solar cells combining interdigitated back contacts and an amorphous silicon or crystalline silicon heterojunction. The photoconversion efficiency is over 26% with a 180.4 cm2 designated area, which is an improvement of 2.7% relative to the previous record efficiency of 25.6%. The cell was analysed to characterize lifetime, quantum efficiency, and series resistance, which are essential elements for conversion efficiency. Finally, a loss analysis pinpoints a path to approach the theoretical conversion efficiency limit of silicon solar cells at 29.1%.