High Current Density in Monolayer MoS2 Doped by AlOx

Semiconductors require stable doping for applications in transistors, optoelectronics, and thermoelectrics. However, this has been challenging for two-dimensional (2D) materials, where existing approaches are either incompatible with conventional semiconductor processing or introduce time-dependent, hysteretic behavior. Here we show that low-temperature (<200 degrees C) substoichiometric AlOx provides a stable n-doping layer for monolayer MoS2, compatible with circuit integration. This approach achieves carrier densities >2 x 10(13) cm(-2), sheet resistance as low as similar to 7 k Omega/square, and good contact resistance similar to 480 Omega.mu m in transistors from monolayer MoS2 grown by chemical vapor deposition. We also reach record current density of nearly 700 mu A/mu m (>110 MA/cm(2)) along this three-atom-thick semiconductor while preserving transistor on/off current ratio >10(6). The maximum current is ultimately limited by self-heating (SH) and could exceed 1 mA/mu m with better device heat sinking. With their 0.1 nA/mu m off-current, such doped MoS2 devices approach several low-power transistor metrics required by the international technology roadmap.