On the 29th, Lee Seung-woo, a professor at Korea University Graduate School of Convergence and the Department of Convergence Energy Engineering, announced that his research team has developed a transparent radiative cooling film applicable to vehicle glass and protective glass surfaces for solar cells.
Radiative cooling is next-generation thermal management technology that can emit heat into space without mechanical cooling devices. Professor Lee's research team applied this principle to create a transparent film that effectively emits heat in specific wavelength ranges that pass through the atmosphere while allowing light to pass through.
To achieve this, the research team applied a design method that arranges silica nanoparticles in a lattice structure within a polymer and stacks a transparent layer on top. They created a material from this that can be coated like ink and then cured with ultraviolet light to produce the film, confirming that this method enables large-area and mass production of films without complex micro-processing. Furthermore, by adjusting the particle size and density, they produced not only transparent films but also colored films, ensuring that performance does not degrade even with added colors, thereby securing both aesthetics and functionality.
In fact, when the film was attached to a solar cell, it was found that the surface temperature of the solar cell decreased by about 5.77 degrees, and the power conversion efficiency improved by approximately 2%. Power conversion efficiency refers to the ratio of light energy absorbed by the solar cell that is converted into electricity. Through this, the research team demonstrated that the transparent radiative cooling film can contribute to temperature reduction and improved solar cell performance.
Professor Lee stated, "This research demonstrates the practicality and applicability of transparent radiative cooling films," adding, "It has opened up the possibility of a new cooling material that can be expanded into various fields such as automotive, construction, and solar power generation."
This research achievement was published online on July 9 in the international journal of energy and materials, Advanced Functional Materials.
References
Advanced Functional Materials (2025), DOI: https://doi.org/10.1002/adfm.202510833