Self-cleaning effect of highly water-repellent microshell structures for solar cell applications

A self-cleaning effect developed through the use of a superhydrophobic and water-repellent surface was demonstrated for solar cell applications. A perfectly ordered microshell array was fabricated on a transparent and flexible polydimethylsiloxane (PDMS) elastomer surface. This microshell PDMS showed an excellent water-repellent property with a contact angle (CA) higher than 150 degrees and a hysteresis of lower than 20 degrees, even without the aid of a low surface energy chemical coating. Fabricated superhydrophobic microshell PDMS showed a superior dust cleaning effect compared to that of flat PDMS, preventing the degradation by dust particles of solar cell efficiency. This transparent, flexible and superhydrophobic microshell PDMS surface provides feasibility for a practical application of superhydrophobic surfaces in solar cells.