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Structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond films
journal contributionposted on 2019-05-14, 13:23 authored by H Xu, J Liu, H Ye, D Coathup, AV Khomich, X Hu
We investigate the structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond (UNCD) films. Impedance spectroscopy measurements show that the impedance of diamond grains is relatively stable, while that of grain boundaries (GBs) (R b) significantly increases after the C+ implantation, and decreases with the increase in the annealing temperature (T a) from 650 °C to 1000 °C. This implies that the C+ implantation has a more significant impact on the conductivity of GBs. Conductive atomic force microscopy demonstrates that the number of conductive sites increases in GB regions at T a above 900 °C, owing to the formation of a nanographitic phase confirmed by high-resolution transmission electronic microscopy. Visible-light Raman spectra show that resistive trans-polyacetylene oligomers desorb from GBs at T a above 900 °C, which leads to lower R b of samples annealed at 900 and 1000 °C. With the increase in T a to 1000 °C, diamond grains become smaller with longer GBs modified by a more ordered nanographitic phase, supplying more conductive sites and leading to a lower R b.
Project supported by the National Natural Science Foundation of China (Grant Nos. 50972129 and 50602039), the International Science Technology Cooperation Program of China (Grant No. 2014DFR51160), the National Key Research and Development Program of China (Grant No. 2016YFE0133200), European Unio's Horizon 2020 Research and Innovation Staff Exchange (RISE) Scheme (Grant No. 734578), One Belt and One Road International Cooperation Project from the Key Research and Development Program of Zhejiang Province, China (Grant No. 2018C04021), and Xinmiao Talents Program of Zhejiang Province, China (Grant No. 2017R403078).
CitationChinese Physics B, 2018, 27 (9), pp. 096104-1-096104-8 (8)
Author affiliation/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Engineering
- AM (Accepted Manuscript)