Room-temperature printing of ultrathin Quasi-2D GaN semiconductor via liquid metal gallium surface confined nitridation reaction

TL;DR

This paper presents a novel room-temperature, liquid metal-based method for synthesizing and printing ultrathin quasi-2D GaN semiconductors, enabling cost-effective fabrication of electronic devices with high performance.

Contribution

First demonstration of room-temperature, liquid metal gallium surface nitridation for large-area quasi-2D GaN synthesis and printing, compatible with electronics manufacturing.

Findings

Achieved p-type field-effect transistors with >10^5 on/off ratio

Maximum hole mobility of 53 cm²/(V·s)

GaN thickness from 1nm to nanometers at room temperature

Abstract

Outstanding wide-bandgap semiconductor material such as gallium nitride (GaN) has been extensively utilized in power electronics, radiofrequency amplifiers, and harsh environment devices. Due to its quantum confinement effect in enabling desired deep-ultraviolet emission, excitonic impact, and electronic transport features, two-dimensional (2D) or ultrathin quasi-2D GaN semiconductors have been one of the most remarkable candidates for future growth of microelectronic devices. Here, for the first time, we reported a large area, wide bandgap, and room-temperature quasi-2D GaN synthesis and printing strategy through introducing the plasma medicated liquid metal gallium surface-confined nitridation reaction mechanism. The developed direct fabrication and compositional process is consistent with various electronics manufacturing approaches and thus opens an easy going way for cost-effective growth of the third-generation semiconductor. In particular, the fully printed field-effect transistors relying on the GaN thus made show p-type switching with an on/off ratio greater than 105, maximum field-effect hole mobility of 53 cm2/(V*s), and a small sub-threshold swing. As it was demonstrated, the present method allows to produce at room temperature the GaN with thickness spanning from 1nm to nanometers. This basic method can be further extended, generalized, and utilized for making various electronic and photoelectronic devices in the coming time.