Domestic researchers have succeeded in developing a smart window-type organic functional film that generates electricity using sunlight and simultaneously controls light brightness.


A research team led by Dr. Soyeon Kim and Dr. Dongchan Lim of the Energy and Electronic Materials Research Laboratory at the Korea Institute of Materials Science (KIMS, President Lee Jeong-hwan), a government-funded research institute under the Ministry of Science and ICT, has developed the nation's first organic-based smart window film. The researchers confirmed that this technology improves the efficiency and transparency of organic solar cells and demonstrates excellent performance not only in large-area flexible modularization but also after integration with electrochromic films.

Smart windows can reduce energy loss in buildings by adjusting brightness through color changes depending on the situation. However, existing smart window technology is based on inorganic materials, requiring high-temperature processes or exhibiting issues in terms of flexibility. The research team solved this problem by fabricating high-performance solar cells and electrochromic devices based on organic materials.

The research team fabricated high-efficiency organic solar cells by introducing organic molecules between the electron transport layer and the photoactive layer. This enhanced flexibility by improving interfacial junction characteristics between the two layers and enabled good performance even in large-area devices. In particular, using this technology, we succeeded in fabricating an organic electrochromic-solar cell hybrid module that not only generates electricity but also self-regulates light brightness using the electrical energy from the solar cells.

The market size of smart windows is projected to reach approximately $82.3 billion (about 94 trillion won) as of 2023, and the market outlook is bright due to the government's carbon neutrality and Green New Deal policies. Smart windows equipped with this technology can be applied not only to existing buildings but also to areas with curvature, so it is expected that expansion into various markets such as automobiles and aircraft will be possible in the future.

"Senior Researcher Kim So-yeon, the principal investigator, stated, 'This research is highly significant in that it presents a new direction for the smart window market by integrating high-performance solar cells and electrochromic devices based on organic materials.'"

In addition, Principal Researcher Lim Dong-chan stated, “We expect to make a significant contribution to the construction of smart cities in the future through the convergence of organic solar cells and electrochromic devices with Internet of Things (IoT) sensors.”

This research achievement was carried out with the support of the Ministry of Science and ICT’s Materials Innovation Leading Project and the Ministry of Trade, Industry and Energy’s Energy Technology Development Project, and in 2021, through the Ministry of Trade, Industry and Energy’s Smart Specialization Infrastructure Establishment Project, it is planned to develop mass production technology and support related companies.

Meanwhile, the results of this study were published on March 3 in 'Communications Materials,' a sister journal of the world-renowned journal Nature, on May 7 in 'Advanced Science' and on May 30 in 'Chem Sus Chem,' and were simultaneously published online in the 'Chemical Engineering Journal' on April 7 and June 18, respectively.