Stable Nitric Oxide Doping in Monolayer WSe2 for High-Performance P-type Transistors

Abstract Thanks to their atomically thin body, two-dimensional (2D) semiconductors are promising candidates for beyond-silicon electronic devices. However, excessive contact resistance and limited threshold voltage control due to ineffective or non-existent doping techniques hinder their technological readiness. Here, we unveil the doping mechanism of pure nitric oxide (NO) and demonstrate its effectiveness on wafer-scale grown monolayer tungsten diselenide (1L-WSe₂) transistors. This novel doping approach, combined with a scaled high-κ dielectric, yields WSe₂ transistors with exceptional performance metrics: a high on-state current of 300 µA/µm (at a drain-to-source voltage of -1 V and overdrive voltage of -0.8 V), low contact resistance of 875 Ω μm, peak transconductance of 400 µS/µm, and a near-ideal subthreshold swing of 70 mV/dec, while preserving large on/off ratios (> 10⁹), minimal variability, and excellent stability after 24 days. Our findings establish NO doping as a powerful method for realizing high-performance p-type 2D transistors and advancing next-generation ultra-scaled electronic devices.