Micro-Raman, SEM, XPS, and electron field emission characterizations of nitrogen-induced shallow defects on nanodiamond films fabricated with different growth parameters

• Published in: Diamond and related materials 2009-02, Vol.18 (2), p.191-195
• Main Authors: LeQuan, X.C., Kang, W.P., Davidson, J.L., Guo, M., Choi, B.K.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Disorder; Electron and ion emission by liquids and solids; impact phenomena; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Field emission, ionization, evaporation, and desorption; Fullerenes and related materials; diamonds, graphite; Grain boundary; Materials science; Nanodiamond film; Nitrogen; Physics; Shallow defect; Specific materials; Structure and morphology; thickness; Surface and interface electron states; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2008.12.003

Nitrogen-induced shallow defects on nanodiamond films have been systematically characterized as a function of growth parameters using micro-Raman, SEM, XPS, and field emission measurements. Distinct peaks indicating diamond and graphite phases were observed in the micro-Raman spectroscopy. The increased in peak intensity and peak shifts due to growth parameters including pressure, power, and nitrogen flow-rate were observed and explained. The electronic behavior is further supplemented with SEM and XPS studies. Finally, electron field emission measurement is used to verify the deduced findings. The result of this study indicates that depending on the growth conditions nitrogen can act as a shallow donor in nanodiamond due to the formation of shallow defects with effective work functions ranging between 0.023 eV and 0.045 eV, as deduced from field emission characteristics. The correlation of film morphologies, spectroscopic analysis and field emission measurements to the growth conditions provide a better understanding of the nitrogen-induced shallow defects on the electronic properties of nanodiamond films.