Plasma-Assisted Nitrogen Doping of Langmuir–Blodgett Self-Assembled Graphene Films

Condensed Matter

article

Tijana Tomašević-Ilić¹  Nikola Škoro¹  Đorđe Jovanović¹  Nevena Puač¹  Marko Spasenović² 

[1]Institute of Physics Belgrade, University of Belgrade

[2]Center for Microelectronic Technologies, Institute of Chemistry, Technology and Metallurgy, University of Belgrade

关键词: graphene;    liquid phase exfoliation (LPE);    Langmuir–Blodgett assembly;    nitrogen doping;    low-temperature plasma;   

DOI  :  10.3390/condmat8020034

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

Graphene films prepared from solution and deposited by Langmuir–Blodgett self-assembly technique (LBSA) were treated with radio-frequency (13.56 MHz) nitrogen plasma in order to investigate the influence of the time of nitrogen plasma exposure on the work function, sheet resistance, and surface morphology of LBSA graphene films. Kelvin probe force microscopy and sheet resistance measurements confirm nitrogen functionalization of our films, with the Fermi level shifting in a direction that indicates binding to a pyridinic and/or pyrrolic site. Upon 1 min of nitrogen plasma exposure, the sheet resistance decreases and there is no obvious difference in film morphology. However, plasma exposure longer than 5 min leads to the removal of graphene flakes and degradation of graphene films, in turn, affecting the flake connectivity and increasing film resistance. We show that by changing the exposure time, we can control the work function and decrease sheet resistance, without affecting surface morphology. Controllability of the plasma technique has an advantage for graphene functionalization over conventional doping techniques such as chemical drop-casting. It allows for the controllable tuning of the work function, surface morphology, and sheet resistance of LBSA graphene films, which is substantial for applications in various optoelectronic devices.

【 授权许可】

CC BY