The intrinsic (trap-free) transistors based on perovskite single crystals with self-passivated surfaces

TL;DR

This paper reports the development of high-performance, trap-free perovskite FETs using epitaxial single crystals of CsPbBr3, enabling detailed charge transport studies and advancing perovskite device technology.

Contribution

It introduces a novel vapor-phase epitaxy method for large-area, high-quality perovskite films and demonstrates their application in high-mobility FETs with low hysteresis.

Findings

Charge carrier mobility increases from 30 to 250 cm2V-1s-1 when cooled from room temperature to 50 K.

First-time Hall effect measurements in perovskite FETs show band transport limited by phonon scattering.

Epitaxial growth techniques can be extended to other perovskite materials.

Abstract

Lead-halide perovskites emerged as novel semiconducting materials suitable for a variety of optoelectronic applications. However, fabrication of reliable perovskite field-effect transistors (FETs), the devices necessary for the fundamental and applied research on charge transport properties of this class of materials, has proven challenging. Here we demonstrate high-performance perovskite FETs based on epitaxial, single crystalline thin films of cesium lead bromide (CsPbBr3). An improved vapor-phase epitaxy has allowed growing truly large-area, atomically flat films of this perovskite with excellent structural and surface properties. FETs based on these CsPbBr3 films exhibit textbook transistor characteristics, with a very low hysteresis and high intrinsic charge carrier mobility. Availability of such high-performance devices has allowed the study of Hall effect in perovskite FETs for the first time. Our magneto-transport measurements show that the charge carrier mobility of CsPbBr3 FETs increases on cooling, from ~ 30 cm2V-1s-1 at room temperature, to ~ 250 cm2V-1s-1 at 50 K, exhibiting a band transport mostly limited by phonon scattering. The epitaxial growth and FET fabrication methodologies described here can be naturally extended to other perovskites, including the hybrid ones, thus representing a technological leap forward, overcoming the performance bottleneck in research on perovskite FETs.