For decades, the pursuit of faster, more efficient electronics has been hampered by a stubborn asymmetry: while n-type semiconductors that carry electrons have advanced rapidly, their p-type counterparts that transport positive charge carriers have lagged behind. This imbalance limits the design of complementary circuits that slash power consumption in everything from smartphones to data centers. Now, a team led by Professor Yong-Young Noh at Pohang University of Science and Technology (POSTECH) has shattered that bottleneck with a tin-based perovskite transistor that not only delivers record p-type performance but does so while surviving in open air—a feat long thought impossible for this class of materials. The work, published in Nature, marks the first time a perovskite transistor has appeared in the journal, effectively launching a new research frontier.
The core challenge lies in the very chemistry that makes tin perovskites so attractive. Cesium tin iodide (CsSnI₃) exhibits exceptionally high hole mobility, rivaling low-temperature polycrystalline silicon and oxide semiconductors that drive high-resolution displays and memory. However, the material is fatally reactive: unreacted tin ions (Sn²⁺) on its surface oxidize almost instantly upon exposure to air, forming a dense layer of defects that trap charge carriers and collapse device performance within minutes. “Air is absolutely essential for human life, but for these semiconductors, it is a deadly poison,” Noh remarks, encapsulating the paradox that has kept perovskite transistors confined to inert gloveboxes.
The POSTECH team’s solution is a process they call Volatile Surface Reconstruction. They treated the CsSnI₃ film with potassium acetate (KAc), which triggers a targeted chemical reaction. The problematic excess Sn²⁺ ions are converted into tin acetate (Sn(Ac)₂), a compound that is volatile under processing conditions and simply evaporates away. Crucially, the potassium ions from the acetate simultaneously react with iodide in the perovskite to form a thin, conformal layer of potassium iodide (KI) that fills the vacancies left behind. This KI skin acts as a self-assembled protective barrier, shielding the underlying semiconductor from oxygen and moisture without impeding charge transport. “It’s a two-birds-with-one-stone solution,” explains Noh. “The troublemaker is removed, and the gap it leaves is immediately sealed.”
The electrical results are striking. The thin-film transistors exhibit a hole mobility exceeding 50 cm²/V·s, a threshold voltage that is significantly reduced for low-power operation, and an on/off current ratio surpassing 10⁸—meaning the device can switch between conducting and insulating states with a contrast of one hundred million to one. These metrics place the perovskite transistor in direct competition with established p-type technologies, but with the added advantage of low-temperature solution processability that could slash manufacturing costs.
More impressive than the raw numbers is the air stability. Conventional tin perovskite transistors fail within minutes when taken out of a nitrogen atmosphere. The reconstructed devices, by contrast, maintained full operation for more than four hours in open air, and extensive accelerated aging tests showed no degradation after more than a month at 100 °C. This thermal robustness is particularly significant for real-world applications, where chips routinely experience elevated temperatures during operation and packaging. The self-protective KI layer remains intact even after extended thermal stress, suggesting a generalizable strategy for other unstable semiconducting materials.
The underlying mechanism was validated through a combination of spectroscopic and computational analyses performed with collaborators at Sungkyunkwan University and the University of Electronic Science and Technology of China. X-ray photoelectron spectroscopy confirmed the complete removal of metallic Sn⁰ species and the formation of KI at the interface, while density functional theory calculations revealed that the KI layer creates an electronically benign passivation that does not trap holes. This interdisciplinary approach not only explains the device behavior but also provides a rational framework for designing other air-stable perovskite systems.
The implications of the advance ripple across the semiconductor industry. P-type transistors are essential for CMOS (complementary metal–oxide–semiconductor) logic, which forms the backbone of all digital integrated circuits. A high-mobility, air-stable p-channel transistor that can be fabricated at low temperatures opens the door to monolithic 3D integration, where logic and memory stacks are built directly on top of each other to reduce footprint and energy consumption—a critical need for AI-driven computation. Moreover, display driver circuits, which require balanced n- and p-type devices, could be manufactured on flexible substrates for next-generation wearable electronics.
Professor Noh credits the sustained support of Samsung Display and Korea’s Ministry of Science and ICT, who believed in a topic many considered impossible. “Over six years of steady funding, we were able to transform a fragile laboratory curiosity into a robust device platform,” he says. The team is now optimizing the process for large-area uniformity and exploring its applicability to other perovskite chemistries. With this breakthrough, tin perovskite transistors have graduated from delicate glovebox experiments to viable candidates for the future of electronics.
Subject of Research: Air-stable p-type tin perovskite transistors via volatile surface reconstruction.
Article Title: Tin perovskite transistors stabilized through volatile coordination
News Publication Date: 1-Jul-2026
Web References: https://doi.org/10.1038/s41586-026-10714-1
References: Park, G., Lee, D.-H., Reo, Y. et al. Tin perovskite transistors stabilized through volatile coordination. Nature (2026). DOI: 10.1038/s41586-026-10714-1
Image Credits: POSTECH
