Multifunctional Cyanuric Fluoride-Mediated Crystallization and Defect Passivation for 2D Sn-Based Perovskite...

Area of Science:

• Materials Science
• Semiconductor Physics
• Nanotechnology

Background:

• Tin (Sn)-based halide perovskites offer eco-friendly alternatives to lead-based materials for thin-film transistors (TFTs) due to their p-type conductivity.
• Key challenges include Sn²⁺ oxidation, poor film morphology, and high defect densities, limiting device performance.

Purpose of the Study:

• To investigate the efficacy of cyanuric fluoride (Cy-F) as a multifunctional additive for 2D phenylethylamine iodide (PEA₂SnI₄) perovskite films.
• To enhance film quality, suppress defects, and improve the performance and stability of Sn-based perovskite TFTs.

Main Methods:

• Incorporation of cyanuric fluoride (Cy-F) as an additive into 2D phenylethylamine iodide (PEA₂SnI₄) perovskite films.
• Characterization of film morphology, defect density, and charge transport properties using device performance metrics.
• Evaluation of device stability under operational stress conditions.

Main Results:

• Cy-F addition led to uniform, well-oriented films by enhancing PEA⁺ anchoring, suppressing Sn²⁺ oxidation, reducing pinholes, and passivating defects.
• Optimized 12 vol% Cy-F doping resulted in a mobility of 1.88 cm²V^-1s^-1, over a tenfold increase from the pristine device (0.15 cm²V^-1s^-1).
• Interface trap density decreased from 9.8 × 10¹² to 1.8 × 10¹² cm^-2eV^-1, significantly reducing hysteresis; the doped TFT retained 90% of its initial drain current after 2000 s of negative bias stress.

Conclusions:

• Cyanuric fluoride (Cy-F) is a highly effective additive for optimizing the morphology and charge transport in Sn-based perovskite films.
• This strategy provides a new pathway for developing high-performance and stable tin-based perovskite thin-film transistors.
• The findings highlight the potential of Cy-F in advancing eco-friendly semiconductor technologies.