A mixed-dimensional WS2/GaSb heterojunction for high-performance p–n diodes and junction field-effect transistors

Abstract

GaSb nanowires integrated on a silicon-based substrate are of great significance for p-type field-effect transistors. In particular, chips are becoming more and more miniaturized, and complicated dielectric engineering needs to be avoided. Therefore, the introduction of junction field-effect transistor (JFET) can be used to improve the performance of transistors. We demonstrated a heterostructure p-channel depletion type GaSb junction field-effect transistor by combining with n-WS₂ sheets. Typical diode characteristics are observed in n-WS₂/p-GaSb heterostructure diodes, with a high rectification ratio of ∼10⁴. The JFET has excellent electrical features with an ON/OFF ratio of ∼10⁴ and the sub-threshold swing (SS ≈ 723 mV dec⁻¹). With the back gate control the ON/OFF current ratio is improved to ∼10⁶ and the low SS is restrained to 166 mV dec⁻¹. Moreover, due to the electrical properties of the heterojunction the JFET and p–n diodes maintain good stability at high temperatures. Therefore, the WS₂/GaSb heterojunction enables the miniaturization of an integrated power electronic system and provides a promising route to low power electronics.