[15a-4F-1~9] 6.2 Carbon-based thin films

[15a-4F-4] Characterization of N-doped DLC Thin Films using Photoelectron Spectroscopy

〇Yuma Murata¹, Ichihara Fumihiko¹, Ono Hiroshi¹, Cheow-keong Choo², Kuwahara Daisuke¹, Katsumi Tanaka¹ (1.Univ. of Electro-Comm., 2.Univ. of Electro-Comm, CIPE)

Keywords:amorphous carbon,Photoelectron Spectroscopy,Nitrogen-doped

Nitrogen-doped DLC thin films prepared by a hydrocarbon pyrolysis method were characterized with X-ray photoelectron spectroscopy/ultraviolet photoelectron spectroscopy (XPS/UPS) in terms of their chemical bonding state and electronic structure. The C1s core-level shifts showed that N-doping leads the shift towards higher binding energy of C1s due to the formation of C-N bonding. The N1s core level spectra were deconvoluted into three components, approximately 398.5 eV (peak 1), 401 eV (peak 2) and 403 eV (NOx). We interpreted that peak 1 and peak 2 are associated with N atoms bonded to the hybridized sp³ C (N-sp³C) and N atoms bonded to the hybridized sp² C (N-sp²C), respectively. The UPS valence-band spectra of N-doped DLC and Non-doped DLC contain two main features, which assigned to the C 2pπ around ~4 eV and C 2pσ around ~7 ev, respectively. The N-doping dramatically changes p-π and p-σ density-of-states (DOS). Furthermore, we observed the localized states near the Fermi level for N-doped DLC, which are considered to be responsible for the change of the physical and electronic properties induced by N-doping. In this work, we discuss the effect of nitrogen incorporation into amorphous carbon on the electronic structure.