A-site cation–pseudohalide co-design for tin halide perovskite transistors
5 affiliations
- 1Department of Organic and Nano Engineering, Hanyang University, Seoul 04763, Korea.
- 2Human-Tech Convergence Program, Hanyang University, Seoul 04763, Korea.
- 3Department of Chemical Engineering, Hanyang University, Seoul 04763, Korea.
- 4Department of Semiconductor Engineering, Hanyang University, Seoul 04763, Korea.
- 5Institute of Nano Science and Technology, Hanyang University, Seoul 04763, Korea.
Abstract
Tin halide perovskites are promising lead-free semiconductors for next-generation electronics; however, their implementation is constrained by a fragile crystal framework, facile Sn²⁺ oxidation, and rapid crystallization kinetics. Here, we establish a molecular design principle for non-metallic thiocyanate (SCN⁻) additives that stabilizes the formamidinium tin iodide (FASnI₃) lattice and enables high-performance, stable p-channel thin-film transistors (TFTs). Density functional theory calculations reveal that the Sn-X-Sn bond strength in the lattice and the halide migration barriers can be tuned by the size of the A-site cation and its hydrogen-bonding capability with SCN⁻ and I⁻. In particular, we find that both the Sn-SCN-Sn bonding interaction and the iodine migration barrier are maximized when guanidinium thiocyanate (GuaSCN) is employed. Consistently, GuaSCN enhances the crystallinity and grain size of tens-of-nanometer-thick FASnI₃ films, prolongs carrier lifetimes, and suppresses Sn⁴⁺ formation, without altering the intrinsic bandgap. TFTs incorporating GuaSCN achieve a field-effect mobility above 88 cm² V⁻¹ s⁻¹, an Ion/off ratio exceeding 4 × 10⁹, negligible hysteresis, and superior operational and shelf stability across hundreds of devices.
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BibTeX
@article{jeong2026asite,
title = {{A-site cation–pseudohalide co-design for tin halide perovskite transistors}},
author = {Bum Ho Jeong and Cheong Beom Lee and Hansol Park and Seung Yoon Shin and Soobin Heo and Kyeounghak Kim and Hui Joon Park},
journal = {Science Advances},
year = {2026},
month = oct,
doi = {10.1126/sciadv.aeh2062},
url = {https://www.science.org/doi/abs/10.1126/sciadv.aeh2062},
note = {CC BY},
}
RIS
TY - JOUR
TI - A-site cation–pseudohalide co-design for tin halide perovskite transistors
AU - Bum Ho Jeong
AU - Cheong Beom Lee
AU - Hansol Park
AU - Seung Yoon Shin
AU - Soobin Heo
AU - Kyeounghak Kim
AU - Hui Joon Park
PY - 2026
DA - 2026/10/30
JO - Science Advances
DO - 10.1126/sciadv.aeh2062
UR - https://www.science.org/doi/abs/10.1126/sciadv.aeh2062
AB - Tin halide perovskites are promising lead-free semiconductors for next-generation electronics; however, their implementation is constrained by a fragile crystal framework, facile Sn²⁺ oxidation, and rapid crystallization kinetics. Here, we establish a molecular design principle for non-metallic thiocyanate (SCN⁻) additives that stabilizes the formamidinium tin iodide (FASnI₃) lattice and enables high-performance, stable p-channel thin-film transistors (TFTs). Density functional theory calculations reveal that the Sn-X-Sn bond strength in the lattice and the halide migration barriers can be tuned by the size of the A-site cation and its hydrogen-bonding capability with SCN⁻ and I⁻. In particular, we find that both the Sn-SCN-Sn bonding interaction and the iodine migration barrier are maximized when guanidinium thiocyanate (GuaSCN) is employed. Consistently, GuaSCN enhances the crystallinity and grain size of tens-of-nanometer-thick FASnI₃ films, prolongs carrier lifetimes, and suppresses Sn⁴⁺ formation, without altering the intrinsic bandgap. TFTs incorporating GuaSCN achieve a field-effect mobility above 88 cm² V⁻¹ s⁻¹, an Ion/off ratio exceeding 4 × 10⁹, negligible hysteresis, and superior operational and shelf stability across hundreds of devices.
SN - 2375-2548
ER -