An unexploited property of graphene-based heterojunctions is the tunable doping of the junction via electrostatic gating. This unique property may be key in advancing electronic transport across interfaces with semiconductors. Here, we engineer transport in semiconducting TMDs by constructing a lateral heterostructure with epitaxial graphene and tuning its intrinsic doping to form a p–n junction between the graphene and the semiconducting TMDs. Graphene grown on SiC (epitaxial graphene) is intrinsically doped via substrate polarization without the introduction of an external dopant, thus enabling a platform for pristine heterostructures with a target band alignment. We demonstrate an electrostatically tunable graphene/MoS₂ p–n junction with >20× reduction and >10× increased tunability in contact resistance (R_c) compared with metal/TMD junctions, attributed to band alignment engineering and the tunable density of states in graphene. This unique concept provides improved control over transport across 2D p–n junctions.

石墨烯基异质结的未利用特性是可通过静电门控对结进行可调掺杂。这种独特的性质可能是推动跨半导体接口电子传输的关键。在这里，我们通过用外延石墨烯构建横向异质结构并调整其固有掺杂来形成石墨烯与半导体TMD之间的p–n结，从而设计了半导体TMD中的传输。在SiC上生长的石墨烯（外延石墨烯）通过衬底极化固有地掺杂，而无需引入外部掺杂剂，从而为具有目标带对准的原始异质结构提供了平台。我们演示了静电可调石墨烯/ MoS ₂ p–n与金属/ TMD结相比，该结的接触电阻（R _c）降低了20倍以上，可调谐性提高了10倍以上，这归因于能带对齐工程和石墨烯中状态的可调谐密度。这个独特的概念可以更好地控制2D p – n交叉点之间的传输。