Professor Yoon-Bong Hahn (Chemical Engineering) and his doctoral students have developed a technique to manufacture perovskite solar cells using nanocomposite materials and interfacial engineering technology.

The perovskite solar cell using the technology turned out to be very stable when exposed to air, and it lives longer than conventional solar cells thanks to its excellent device performance.

The research outcome was published in the October issue of Nano Energy (IF = 12.343), one of the world-class academic journals in the energy field.

Researchers have conducted studies of perovskite solar cells competitively, because they have a high generating efficiency due to high optical absorption rate, large charge diffusion coefficient, and excellent charge transfer ability, and because they can be mass-produced at a low cost.

However, perovskite solar cells reported so far have had a problem in that the lifetime is remarkably shortened due to photocatalytic phenomenon of the electron transport layer and decomposition of the perovskite material by moisture when exposed to air.

An electron transport layer is a layer in which the exciton of the light absorbing layer is separated into charge and hole by the sunlight and the generated electrons are smoothly moved toward the electrode to generate a current.

Professor Hahn's team had developed a nanocomposite material that hybridized nickel oxide (NiO) nanoparticles with perovskite for the first time, and published the result in Nano Energy last year.

The technique developed this year is to manufacture perovskite solar cells by applying the nanocomposite material and interfacial engineering technology, maintaining the solution state in the atmosphere through all processes.

As a result, the device stabilized after 20 days and the performance of the solar cell was maintained over 90% even after more than 210 days.

This is because the metal oxide interface layer applied to the device structure improves the perovskite crystallinity and suppresses the decomposition of the perovskite material as well as the electron-hole recombination.

"This is an improvement on the problems that are hindering the practical use of perovskite solar cells," said Hahn. "My team's research is meaningful because it's a step closer to commercialization of higher performance solar cells at low prices."

The research was made possible by the support of the Korean Ministry of Science, ICT and Future Planning with the participation of Yousheng Wang, Tahmineh Mahmoudi, Won-Yeop Rho, Hwa-Young Yang, Seunghui Seo, Kiesar Sideeq Bhat, Rafiq Ahmad, and Yoon-Bong Hahn.