High-performance tin-based perovskite field-effect transistors realized by improving film morphology via bifunctional additives

Why this research matters:

Sn-based perovskite semiconductors have emerged as ideal candidates for field-effect transistors (FETs), due to their advantages of low-temperature solution-processability and excellent charge transport properties. However, the fabrication of high-performance and operationally stable Sn-based perovskite transistors remains a significant challenge. The uncontrollable crystallization process results in low-quality perovskite films with low coverage, random orientation and high defect density (grain boundaries and vacancies), disrupt carrier transport pathways, thereby significantly degrading device performance.

Key highlights of this research:

Tailoring a bifunctional additive 4-fluorophenethylamine acetate (FPEAAc) for high-quality Sn-based perovskite films. FPEA⁺ cations serve as a template to induce the oriented growth of perovskite crystals, while Ac^- anions of FPEAAc can coordinate with Sn²⁺ to retard the crystal growth rate and increase the grain size.

To further enhance grain size while avoiding the introduction of excess nucleation sites, they incorporated a small amount of the alkylamine PAAc to further retard the film growth, basing on the optimal template effect of FPEAAc. The resulting FPEAAc/PAAc-modified FET achieved a remarkable mobility of ~40 cm² V⁻¹ s⁻¹, which ranks among the highest reported values for Sn-based perovskite FETs. In addition, the optimized transistors demonstrated excellent operational stability.

Future outlook:

In summary, this work establishes a novel strategy that precisely regulates tin-based perovskite crystallization through templated growth coupled with retarded crystallization, offering novel insights into regulating the film growth of Sn-based perovskites, and thereby advancing the development of high-performance perovskite FETs.

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