Modulation doping and control the carrier concentration in 2-dimensional transition metal dichalcogenides

Abstract: Two-dimensional transition-metal dichalcogenides (TMDs) have attracted interest as post-Si channel candidates in transistor technology. However, despite their potential benefits, controllably doping TMDs has proven difficult. In this work, we proposed a list of candidate elements that can induce p-type and n-type doping in the TMD channel when they are doped onto conventional gate-dielectric oxides. To verify the screened modulation doping candidates, we demonstrate using first-principles calculations the p-doping of monolayer WSe$_2$ by doping Ni int\textbf{}o the interface dielectric HfO$_2$ layer. The induced hole concentration in the WSe$_2$ can be tuned to values compatible with electrostatic gate control of the channel by changing the Ni doping rate. The results of this study will have essential implications for the commercial viability of TMD-based transistors.