Grain Engineering for Improved Charge Carrier Transport in Two-Dimensional Lead-Free Perovskite Field-Effect Transistors
Shuanglong Wang, Sabine Frisch, Heng Zhang, Okan Yildiz, Mukunda Mandal, Naz Ugur, Beomjin Jeong, Charusheela Ramanan, Denis Andrienko, Hai I. Wang, Mischa Bonn, Paul W. M. Blom, Milan Kivala, Wojciech Pisula,* and Tomasz Marszalek*
Wang, S.; Frisch. S.; Zhang, H.; Yildiz, O.; Mandal, M.; Ugur, N.; Jeong, B.; Ramanan, C.; Andrienko, D.; Wang, H.; Bonn, M.; Blom, P. W. M.; Kivala, M.; Pisula, W.; Marszalek, T. Grain Engineering for Improved Charge Carrier Transport in Two-Dimensional Lead-Free Perovskite Field-Effect Transistors. Mater. Horiz. 2022, 9, 2633.
- Large hysteresis and poor field-effect behavior associated with severe ion migration can render perovskite field-effect transistors (FET) unreliable.
- The hot-casting method can be used to control grain size and grain boundary density in perovskite films to improve charge carrier transport.
- Hot-cast Sn(II)-based 2D perovskite FETs containing thiophene-based organic cation spacer TEA showed moderate increases in local hole mobility and significant FET performance improvements.
Controlling crystal growth and reducing the number of grain boundaries are crucial to maximize the charge carrier transport in organic–inorganic perovskite field-effect transistors (FETs). Herein, the crystallization and growth kinetics of a Sn(II)-based 2D perovskite, using 2-thiopheneethylammonium (TEA) as the organic cation spacer, were effectively regulated by the hot-casting method. With increasing crystalline grain size, the local charge carrier mobility is found to increase moderately from 13 cm2 V−1 s−1 to 16 cm2 V−1 s−1, as inferred from terahertz (THz) spectroscopy. In contrast, the FET operation parameters, including mobility, threshold voltage, hysteresis, and subthreshold swing, improve substantially with larger grain size. The optimized 2D (TEA)2SnI4 transistor exhibits hole mobility of up to 0.34 cm−1 s−1 at 295 K and a higher value of 1.8 cm−1 s−1 at 100 K. Our work provides an important insight into the grain engineering of 2D perovskites for high-performance FETs.
- Grain engineering can be used to improve the performance of 2D perovskite FETs.
- Hot-casting method used to control crystallization and growth kinetics of Sn(II)-based 2D perovskite.
- Increasing crystalline grain size leads to moderate increase in local charge carrier mobility and substantial improvement in FET operation parameters.