Doping is required to modulate the electrical properties of semiconductors but introduces impurities that lead to Coulomb scattering, which hampers charge transport. Such scattering is a particular issue in two-dimensional semiconductors because charged impurities are in close proximity to the atomically thin channel. Here we report the remote modulation doping of a two-dimensional transistor that consists of a band-modulated tungsten diselenide/hexagonal boron nitride/molybdenum disulfide heterostructure. The underlying molybdenum disulfide channel is remotely doped via controlled charge transfer from dopants on the tungsten diselenide surface. The modulation-doped device exhibits two-dimensional-confined charge transport and the suppression of impurity scattering, shown by increasing mobility with decreasing temperature. Our molybdenum disulfide modulation-doped field-effect transistors exhibit a room-temperature mobility of 60 cm2 V–1 s–1; in comparison, transistors that have been directly doped exhibit a mobility of 35 cm2 V–1 s–1.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering