Reduction of Hysteresis in Hybrid Perovskite Transistors by Solvent-Controlled Growth

The effect of crystallization process speed on the morphology of solution-processed methyl ammonium lead iodide (MAPbI(3)) thin films is investigated. Crystallization speed is controlled by varying the number of annealing steps, temperature, and resting time between steps. The resting period allows solvent-controlled growth (SCG) in which crystallization progresses slowly via an intermediate phase-during which solvents slowly evaporate away from the films. SCG results in fewer residues, fewer pinholes, and larger grain sizes. Consequently, thin-film transistors with SCG MAPbI(3) exhibit smaller hysteresis in their current-voltage characteristics than those without, demonstrating the benefits of SCG toward hysteresis-free perovskite devices.

Automated summary

The study demonstrates that controlling the crystallization speed can modify the morphology of solution-processed MAPbI(3) thin films, with solvent-controlled growth leading to fewer residues, fewer pinholes, and larger grain sizes. Thin-film transistors with solvent-controlled growth exhibit smaller hysteresis in their current-voltage characteristics, indicating the benefits of solvent-controlled growth towards hysteresis-free perovskite devices.