Creating silicon-based photovoltaics at room temperature

Ongoing challenges in solar cell production could partly explain why non-renewable energy resources — such as coal, oil, and natural gas — have overshadowed current optoelectronic devices. Now, researchers at Kyoto University have found an environmentally friendlier solution with enhanced performance, using PEDOT:PSS/silicon heterojunction solar cells. This hybrid type is made of organic–inorganic material, which could potentially ease the production process compared to conventional silicon-only solar cells.

Lead author Katsuaki Tanabe said the researchers wanted to avoid manufacturing solar cells in vacuums and high-temperature processes, which require large and expensive shipment and great amounts of time. The researchers set out to fabricate solar cells from silicon wafers under only ambient temperature and pressure conditions. However, their efforts yielded worthy results after optimising process conditions for the wafers. These polished wafers were first diced into 8 mm square pieces and coated with PEDIT:PSS aqueous solution and silver electrodes, in a variety of sequences.

“Our approach enabled us to achieve improved production speed at lower cost and with a power generation efficiency above 10%,” Tanabe said.

The researchers suggested that this new, more efficient production process may lead to large-scale diffusion of photovoltaic power generation. This system could see wider utility in various settings, such as in education or in developing economies. “Next, we will focus on optimising impurities and additive concentrations in our production, as well as other structural innovations,” Tanabe said.

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