Year: 2021
Type: article
Abstract: 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 °C) substoichiometric AlO x provides a stable n -doping layer for monolayer MoS 2, compatible with circuit integration. This approach achieves carrier densities >2 × 10 13 cm –2, sheet resistance as low as ∼7 kΩ/□, and good contact resistance ∼480 Ω·μm in transistors from monolayer MoS 2 grown by chemical vapor deposition. We also reach record current density of nearly 700 μA/μm (>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/μm with better device heat sinking. With their 0.1 nA/μm off-current, such doped MoS 2 devices approach several low-power transistor metrics required by the international technology roadmap.
Source: ACS Nano
Institution: Stanford University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3119675150