Gogotsi Y, Libera J A, Kalashnikov N, et al. Graphite polyhedral crystals [J]. Science, 2000, 290 (13):317-320.[2] Jang J, Chung S J, Kim H S, et al. Self-organized carbon nanotips [J]. Appl. Phys. Lett., 2001, 79 (11):1682-1684.[3] Wei J X, Liew K M, He X Q. Mechanical properties of carbon nanocones [J]. Appl. Phys. Lett., 2007, 91 (26):261906-1-3.[4] Zhang Guangyu, Jiang Xin, Wang Enge. Tubular graphite cones [J]. Science, 2003, 300 (5618):472-474.[5] Ostrikov K. Colloquium: Reactive plasmas as a versatile nanofabrication tool [J]. Rev. Mod. Phys., 2005, 77 (2):489-511.[6] Wang B B, Ostrikov K. Tailoring carbon nanotips in the plasma-assisted chemical vapor deposition: Effect of the process parameters [J]. J. Appl. Phys., 2009, 105 (8):083303-1-9.[7] Wang B B, Ostrikov K, Tsakadze Z L, et al. Analysis of photoluminescence background of Raman spectra of carbon nanotips grown by plasma-enhanced chemical vapor deposition [J]. J. Appl. Phys., 2009, 106 (1):013315-1-7.[8] Wang Biben, Dang Chun. Mechanism of photoluminescence from a-C:N:H nanotips [J]. Chin. J. Lumin.(发光学报), 2010, 31 (3):400-404 (in Chinese).[9] Wang B B, Zhang B. Effect of carbon film roughness on growth of carbon nanotip arrays by plasma-enhanced hot filament chemical vapor deposition [J]. Carbon, 2006, 44 (10):1949-1953.[10] Tsakadze Z L, Levchenko I, Ostrikov K, et al. Plasma-assisted self-organized growth of uniform nanocone arrays [J]. Carbon, 2007, 45 (10):2022-2030.[11] Casiraghi C, Piazza F, Ferrari A C, et al. Bonding in hydrogen diamond-like carbon by Raman spectroscopy [J]. Diam. Relat. Mater., 2005, 14 (3-7):1098-1102.[12] Ren Z M, Lu Y F, Ho D H K, et al. Raman spectroscopy studies of the influence of substrate temperature and ion beam energy on CNx thin films deposited by nitrogen-ion-assisted pulsed laser deposition [J]. Jpn. J. Appl. Phys. Part 1, 1999, 38 (8):4869-4862.[13] Zhang Shulin, Wang Xin, Ho Kousan, et al. Raman spectra in broad frequency region of p-type porous silicon [J]. J. Appl. Phys., 1994, 76 (5):3016-3019.[14] Zhang Xugang, Wu Qilin. Raman Spectroscopy Analysis and Application [M]. Beijing: National Defence Inudtry Press, 2008:5 (in Chinese).[15] Vlasov I I, Ralchenko V G, Goovaerts E, et al. Bulk and surface-enhanced Raman spectroscopy of nitrogen-doped ultrananocrystalline diamond films [J]. Phys. Stat. Sol., 2006, 203 (12):3028-3035.[16] Chakrabarti K, Basu M, Chaudhuri S, et al. Photoluminescence studies of DC plasma CVD grown a-C:H:N films [J]. Mater. Chem. Phys., 1999, 59 (1):69-74.[17] Anguita J V, Silva S R P, Young W. Photoluminescence from polymer-like hydrogenated and nitrogenated amorphous carbon films [J]. J. Appl. Phys., 2000, 88 (9):5175-5179.[18] Shen Xuechu. Semiconductor Spectra and Optical Properties [M]. Beijing: Science Press, 2002:303 (in Chinese).[19] Stewart A D G, Thompson M W. Microtopography of surface eroded by ion-bombardment [J]. J. Mater. Sci., 1969, 4 (1):56-60.[20] Silva S R P, Robertson, Amaratunga G A J, et al. Nitrogen modification of hydrogenated amorphous carbon films [J]. J. Appl. Phys., 1997, 81 (6):2626-2634.[21] Robertson J. Recombination and photoluminescence mechanism in hydrogenated amorphous carbon [J]. Phys. Rev. B, 1996, 53 (24):16302-16305.