Professor Ji-sang Park of SAINT has contributed to a collaborative research breakthrough that significantly improves both the performance and stability of tin-based perovskite transistors. The findings were published in Nature.

The research was led by Professor Yong-Young Noh’s team at POSTECH in collaboration with Professor Jisang Park’s team at Sungkyunkwan University and research teams led by Professors Ao Liu and Huihui Zhu at the University of Electronic Science and Technology of China (UESTC).

Tin-based perovskites have attracted significant attention as promising materials for high-performance p-type transistors. However, their practical application has been limited by poor air stability: unreacted tin ions (Sn²⁺) on the material surface readily oxidize when exposed to air, creating defects that rapidly degrade device performance.

To address this challenge, the researchers developed a “volatile surface reconstruction” strategy. By treating the surface of a cesium–tin–iodide semiconductor with potassium acetate, residual tin ions are converted into volatile tin acetate and removed from the surface. At the same time, potassium iodide forms naturally in the resulting vacancies, creating a protective layer against the external environment.

The resulting p-type perovskite transistors achieved hole mobilities exceeding 50 cm²/V·s and on/off current ratios above 10⁸, representing world-leading device performance. The devices also demonstrated substantially improved stability, remaining operational for more than four hours in ambient air and maintaining their initial performance for over a month under accelerated aging conditions at 100°C.

The breakthrough could open new possibilities for high-performance electronic technologies, including vertically stacked DRAM for AI computing, next-generation display driving circuits, wearable electronics, and highly integrated semiconductor devices.