Low-Temperature Nitrogen Doping of Nanocrystalline Graphene Films with Tunable Pyridinic-N and Pyrrolic-N by Cold-Wall Plasma-Assisted Chemical Vapor Deposition

Nur Hamizah Zainal Ariffin; Muhammad Aniq Shazni Mohammad Haniff; Mohd Ismahadi Syono; Mohd Ambri Mohamed; Azrul Azlan Hamzah; Abdul Manaf Hashim

doi:10.1021/acsomega.1c01520

Low-Temperature Nitrogen Doping of Nanocrystalline Graphene Films with Tunable Pyridinic-N and Pyrrolic-N by Cold-Wall Plasma-Assisted Chemical Vapor Deposition

ACS Omega. 2021 Sep 10;6(37):23710-23722. doi: 10.1021/acsomega.1c01520. eCollection 2021 Sep 21.

Authors

Nur Hamizah Zainal Ariffin^{1

2}, Muhammad Aniq Shazni Mohammad Haniff³, Mohd Ismahadi Syono², Mohd Ambri Mohamed³, Azrul Azlan Hamzah³, Abdul Manaf Hashim¹

Affiliations

¹ Advanced Devices and Material Engineering Research Lab, Department of Electronic Systems Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, 51400 Kuala Lumpur, Malaysia.
² Advanced Devices Lab, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur, Malaysia.
³ Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia.

Abstract

We report a viable method to produce nanocrystalline graphene films on polycrystalline nickel (Ni) with enhanced N doping at low temperatures by a cold-wall plasma-assisted chemical vapor deposition (CVD) method. The growth of nanocrystalline graphene films was carried out in a benzene/ammonia/argon (C₆H₆/NH₃/Ar) system, in which the temperature of the substrate heated by Joule heating can be further lowered to 100 °C to achieve a low sheet resistance of 3.3 kΩ sq^-1 at a high optical transmittance of 97.2%. The morphological, structural, and electrical properties and the chemical compositions of the obtained N-doped nanocrystalline graphene films can be tailored by controlling the growth parameters. An increase in the concentration of atomic N from 1.42 to 11.28 atomic percent (at.%) is expected due to the synergetic effects of a high NH₃/Ar ratio and plasma power. The possible growth mechanism of nanocrystalline graphene films is also discussed to understand the basic chemical reactions that occur at such low temperatures with the presence of plasma as well as the formation of pyridinic-N- and pyrrolic-N-dominated nanocrystalline graphene. The realization of nanocrystalline graphene films with enhanced N doping at 100 °C may open great potential in developing future transparent nanodevices.