Solar cells charging forward

Kyoto, Japan -- Ongoing challenges in solar cell production may partly explain why non-renewable energy resources -- such as coal, oil, and natural gas -- have overshadowed current optoelectronic devices. 

Now, researchers at Kyoto University may have found an environmentally friendlier solution with enhanced performance, utilizing 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.

"We wanted to avoid manufacturing solar cells in vacuums and high-temperature processes, which require large and expensive equipment and a great amount of time," explains lead author Katsuaki Tanabe. 

Anticipating a challenge, the team set out to fabricate solar cells from silicon wafers under only ambient temperature and pressure conditions. However, their efforts proved to yield worthy results after optimizing process conditions for the wafers.

These polished wafers were first diced into 8-mm square pieces and coated with PEDOT: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%," remarks the author.

Tanabe's team posits 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 optimizing impurities and additive concentrations in our production, as well as other structural innovations," concludes Tanabe.

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The paper "An all ambient, room-temperature processed solar cell from a bare silicon wafer" appeared on 14 March 2023 in PNAS Nexus, with doi: https://doi.org/10.1093/pnasnexus/pgad067

Contact: Katsuaki Tanabe, Associate Professor/tanabe@cheme.kyoto-u.ac.jp

About Kyoto University

Kyoto University is one of Japan and Asia's premier research institutions, founded in 1897 and responsible for producing numerous Nobel laureates and winners of other prestigious international prizes. A broad curriculum across the arts and sciences at both undergraduate and graduate levels is complemented by numerous research centers, as well as facilities and offices around Japan and the world. For more information, please see: http://www.kyoto-u.ac.jp/en