High-performance p-type bilayer WSe2 field effect transistors by nitric oxide doping

Subir Ghosh; Muhtasim Ul Karim Sadaf; Andrew R Graves; Yikai Zheng; Andrew Pannone; Samriddha Ray; Chung-Yu Cheng; Jeremy Guevara; Joan M Redwing; Saptarshi Das

doi:10.1038/s41467-025-59684-4

High-performance p-type bilayer WSe₂ field effect transistors by nitric oxide doping

Nat Commun. 2025 Jul 1;16(1):5649. doi: 10.1038/s41467-025-59684-4.

Authors

Subir Ghosh^#¹, Muhtasim Ul Karim Sadaf^#¹, Andrew R Graves^{2

3}, Yikai Zheng¹, Andrew Pannone¹, Samriddha Ray¹, Chung-Yu Cheng³, Jeremy Guevara⁴, Joan M Redwing^{2

3

5}, Saptarshi Das^{6

7

8

9}

Affiliations

¹ Engineering Science and Mechanics, Penn State University, University Park, PA, USA.
² 2D Crystal Consortium Materials Innovation Platform, Penn State University, University Park, PA, USA.
³ Materials Science and Engineering, Penn State University, University Park, PA, USA.
⁴ Mechanical Engineering, Florida International University, Miami, FL, USA.
⁵ Electrical Engineering, Penn State University, University Park, PA, USA.
⁶ Engineering Science and Mechanics, Penn State University, University Park, PA, USA. sud70@psu.edu.
⁷ Materials Science and Engineering, Penn State University, University Park, PA, USA. sud70@psu.edu.
⁸ Electrical Engineering, Penn State University, University Park, PA, USA. sud70@psu.edu.
⁹ Materials Research Institute, Penn State University, University Park, PA, USA. sud70@psu.edu.

^# Contributed equally.

Abstract

Two-dimensional (2D) materials are promising candidates for next-generation electronics, but the realization of high-performance p-type 2D field-effect transistors (FETs) has remained challenging, hindering the development of fully integrated 2D complementary metal-oxide-semiconductor (CMOS) technology. Here, we present p-type 2D FETs based on bilayer WSe₂ synthesized via an industry-compatible metal-organic chemical vapor deposition (MOCVD) process. These devices achieve on-state current as high as 421 μA/μm at a drain voltage of 1 V and a gate overdrive voltage of 2.5 V, an on/off current ratio exceeding 10⁷, and a subthreshold swing as low as 75 mV/decade. Key device parameters include a contact resistance down to 1.3 kΩ-µm, a field-effect hole mobility of 16.1 cm²V^-1s^-1, and a peak transconductance of 250 µS/µm. This high performance is enabled by p-type doping through nitric oxide (NO) treatment at 100 °C for 30 minutes. Furthermore, we scaled the channel length down to 50 nm, integrated a high-κ gate dielectric with an equivalent oxide thickness of ~2.3 nm, and analyzed over 300 devices. We also investigated the temporal and thermal stability of p-type doping, providing insights into the underlying NO doping mechanism. Our findings help to address a long-standing challenge in 2D materials research and offer a promising solution to realize high-performance p-type 2D FETs for future CMOS applications.