2D In2Ge2Te6 Crystals for High-Performance p-Channel Transistors

Abstract

Two-dimensional (2D) semiconductors are ideal channel materials for high-speed, low-power transistors in the post-Moore era due to their high mobility and excellent gate-control capacity. However, most existing 2D semiconductors tend to exhibit either n-type or ambipolar behavior. The limited availability of intrinsic p-type 2D semiconductors significantly restricts their application in logic circuits and integrated circuits. Herein, we present the experimental discovery of high-quality In₂Ge₂Te₆ single crystals, which possess a layered structure and exhibit a p-type nature with a low hole-effective mass of 0.27 m₀. The 2D In₂Ge₂Te₆ nanosheets, exfoliated from the bulk crystals, show good stability in air, with thickness-dependent variations in Raman peaks and bandgaps. Furthermore, we have successfully developed high-performance 2D In₂Ge₂Te₆ p-channel transistors, achieving a hole mobility and on/off current ratio up to 43 cm² V^-1 s^-1 and 10⁵ at room temperature, respectively. Thus, In₂Ge₂Te₆ emerges as a promising p-type 2D semiconductor for next-generation electronics.

Keywords: 2D semiconductor; In2Ge2Te6; band structure; chemical vapor transport; field-effect transistors; p-type.