p-Diamond, Si, GaN and InGaAs TeraFETs

Abstract: p-diamond field effect transistors (FETs) featuring large effective mass, long momentum relaxation time and high carrier mobility are a superb candidate for plasmonic terahertz (THz) applications. Previous studies have shown that p-diamond plasmonic THz FETs (TeraFETs) could operate in plasmonic resonant mode at a low frequency window of 200 GHz to ~600 GHz, thus showing promising potential for beyond 5G sub-THz applications. In this work, we explore the advantages of p-diamond transistors over n-diamond, Si, GaN and InGaAs TeraFETs and estimate the minimum mobility required for the resonant plasmons. Our numerical simulation shows that the p-diamond TeraFET has a relatively low minimum resonant mobility, and thus could enable resonant detection. The diamond response characteristics can be adjusted by changing operating temperature. A decrease of temperature from 300 K to 77 K improves the detection performance of TeraFETs. At both room temperature and 77 K, the p-diamond TeraFET presents a high detection sensitivity in a large dynamic range. When the channel length is reduced to 20 nm, the p-diamond TeraFET exhibits the highest DC response among all types of TeraFETs in a large frequency window.