Tech&Innovation

Spray sunblock protecting solar cells

A paper that proposed a technology to protect perovskite solar cells from moisture and turn them into useful visible light by blocking ultraviolet light that causes “aging” cells was published in the Advanced Energy Material.

This paper by Professor Kwon Tae-hyuk, Seo Kwan-yong, and Jang Sung-yeon of UNIST proposed multi-functional perovskite battery coating material and coating method that change ultraviolet light into visible light while preventing moisture. Organic metals, which strengthen the properties of pushing water (water-repellent), are applied to cells in an “ultra-sound spray method,” which solves the chronic problems (water vulnerability) of perovskite solar cells and has also increased battery efficiency.

Photo by UNIST

The organic metal developed by the researchers plays a role in converting ultraviolet rays, which are applied to perovskite, into visible light. It prevents UV rays harmful to cells and turns them into visible light that can be absorbed by perovskite batteries to generate electricity. The researchers effectively blocked moisture and ultraviolet light by strengthening the water-repellency of the organic metal.

The cells coated with organic metals maintained their initial efficiency for nearly 900 hours even at 50-60% humidity, and the cell efficiency was also improved by Photo Downshifting. In addition, the efficiency of the batteries without this coating significantly reduced in half by ultraviolet radiation in 300 hours, while those with coating maintained their initial efficiency.

The research team also developed an economic technique that allows easy coating of the organic metal. It is a method of coating a micro-particle-state complex solution very thinly using compressed nitrogen gas. Unlike conventional processes, the top and sides of the substrate can be coated simultaneously.

This study is significant in that multi-functional protective membranes were created through a single substance (organic metal) and a single process. It is considered valuable research as a ‘platform’ technology that can be applied to not only tp perovskite solar cells but also other solar cells.

Source: Hwang, E., Kim, H., Lee, S. ‐. H., Seo, J. H., Kim, H. ‐. T., Lee, C., Jang, S. ‐. Y., Seo, K., & Kwon, T. ‐. H. (2020). Fabrication of Water‐Repellent Platinum(II) Complex‐Based Photon Downshifting Layers for Perovskite Solar Cells by Ultrasonic Spray Deposition. Advanced Energy Materials, 10(36), 2001238. https://doi.org/10.1002/aenm.202001238

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