High Hole Mobility Inorganic Halide Perovskite Field-Effect Transistors with Enhanced Phase Stability and Interfacial Defect Tolerance

So far, it has been difficult to fabricate thin-film field-effect transistors (TFTs) based on inorganic halide perovskites (IHPs) due to their phase-instability and uncontrollable trap density. Here, the bottom-gate bottom-contact structured p-type TFTs are presented using the optimized IHP in the active layer. The stable cubic-CsPbI3 phase is successfully synthesized by doping bismuth iodide and reduced defect densities by adding potassium bromide. The IHP TFTs based on the tailored cubic-CsPbI3 show high hole mobility of approximate to 10 cm(2) V-1 s(-1), an on-off current ratio of 10(3), and a low subthreshold swing voltage of 0.43 V dec(-1). In addition, the operational stability of the fabricated device is demonstrated through the bias stress test. This study suggests that one of the key factors for fabricating an ideal p-type IHP transistor is managing charge transport properties in the IHP layer through defect engineering.

Automated summary

This study presents a novel bottom-gate bottom-contact structured p-type TFT using optimized inorganic halide perovskites (IHPs) in the active layer. By doping bismuth iodide and adding potassium bromide, a stable cubic-CsPbI3 phase with reduced defect densities was successfully synthesized. The IHP TFTs demonstrated high hole mobility, on-off current ratio, and low subthreshold swing voltage, highlighting the importance of defect engineering in managing charge transport properties for ideal p-type IHP transistors.