A research team composed of Professor Seok-in Na and Research Professor Seong-nam Kwon of Jeonbuk National University (JBNU)'s Graduate School of Flexible Pinted Electronics has attracted attention for proposing an eco-friendly colloidal ink design strategy that simultaneously enhances the performance of perovskite solar cell modules and the scalability of large-area processing in collaboration with the Daegu Gyeongbuk Institute of Science and Technology (DGIST) and Sungkyunkwan University.

The study involved Dr. Sushil Shivaji Sangale of DGIST and Dr. Daehwan Kim—both of whom received their Ph.D. degrees from JBNU's Graduate School of Flexible Pinted Electronics—and Professor Sae-byeok Cho of Sungkyunkwan University. The research results were published under the title 'Greener Colloidal Ink Engineering and Local Solidification Control for High-Performance Slot-Die Coated Perovskite Solar Modules' in the latest issue of the leading energy materials journal Advanced Energy Materials (IF 26).

Perovskite solar cells have attracted attention as next-generation photovoltaic devices due to their high power conversion efficiency and low manufacturing cost. However, commercialization has been constrained by limitations such as difficulty forming uniform thin films over large areas and reliance on highly toxic solvents like N,N-dimethylformamide (DMF) during processing.

To address these issues, the research team introduced iodobenzene (Iodo) as a functional additive into a dimethyl sulfoxide (DMSO)-based ink system and developed an eco-friendly colloidal ink that completely eliminates highly toxic DMF. This established a foundation for precisely controlling crystallization kinetics and the solidification process during slot-die coating.

In experiments, the team reported achieving a power conversion efficiency (PCE) of 22.3%—the highest level reported for a DMF-free DMSO-based perovskite system. They also demonstrated excellent performance in large-area processing, recording efficiencies of 21% and 19.5% for slot-die coated modules with areas of 2.7 cm² and 31.50 cm², respectively.

Professor Seok-in Na stated, “This study is significant in that it demonstrates the simultaneous achievement of high efficiency and environmental friendliness through colloidal ink design and control of solidification kinetics, while enabling uniform, high-quality thin film formation in large-area processes. We expect this will be an important milestone in accelerating the commercialization of perovskite solar cells.”

Meanwhile, this research was supported by the National Research Foundation of Korea (Mid-career Research, Basic Research Laboratory), Korea Electric Power Corporation, and the Ministry of Science and ICT's InnoCORE program.