Doped graphene could be of use in next-generation electronic and photonic devices. However, chemical doping cannot be precisely controlled in the material and leads to external disorder that diminishes carrier mobility and conductivity. Here we show that graphene can be efficiently doped using a monolayer of tungsten oxyselenide (TOS) that is created by oxidizing a monolayer of tungsten diselenide. When the TOS monolayer is in direct contact with graphene, a room-temperature mobility of 2,000 cm² V⁻¹ s⁻¹ at a hole density of 3 × 10¹³ cm⁻² is achieved. Hole density and mobility can also be controlled by inserting tungsten diselenide interlayers between TOS and graphene, where increasing the layers reduces the disorder. With four layers, a mobility value of around 24,000 cm² V⁻¹ s⁻¹ is observed, approaching the limit set by acoustic phonon scattering, resulting in a sheet resistance below 50 Ω sq⁻¹. To illustrate the potential of our approach, we show that TOS-doped graphene can be used as a transparent conductor in a near-infrared (1,550 nm) silicon nitride photonic waveguide and ring resonator.

掺杂石墨烯可用于下一代电子和光子器件。然而，化学掺杂无法在材料中精确控制，并导致外部无序，从而降低载流子迁移率和导电性。在这里，我们展示了使用通过氧化单层二硒化钨而产生的单层氧硒化钨 (TOS) 可以有效地掺杂石墨烯。当 TOS 单层与石墨烯直接接触时，在 3 × 10 ¹³  cm ^-2的空穴密度下，室温迁移率为 2,000 cm ²  V ^-1  s ^-1已完成。空穴密度和迁移率也可以通过在 TOS 和石墨烯之间插入二硒化钨中间层来控制，其中增加层数可以减少无序。通过四层，观察到大约 24,000 cm ²  V ^-1  s ^-1的迁移率值，接近声子散射设定的极限，导致薄层电阻低于 50 Ω sq ^-1。为了说明我们方法的潜力，我们表明 TOS 掺杂的石墨烯可以用作近红外（1,550 nm）氮化硅光子波导和环形谐振器中的透明导体。