TY - JOUR
T1 - Carbon 1s X-ray photoelectron spectra of realistic samples of hydrogen-terminated and oxygen-terminated CVD diamond (111) and (001)
AU - Kono, Shozo
AU - Kageura, Taisuke
AU - Hayashi, Yuya
AU - Ri, Sung Gi
AU - Teraji, Tokuyuki
AU - Takeuchi, Daisuke
AU - Ogura, Masahiko
AU - Kodama, Hideyuki
AU - Sawabe, Atsuhito
AU - Inaba, Masafumi
AU - Hiraiwa, Atsushi
AU - Kawarada, Hiroshi
PY - 2019/3
Y1 - 2019/3
N2 - Key factors in C 1s photoelectron spectroscopy for realistic samples of single crystal diamonds are remarked. Basic equations for angle-dependent photoelectron spectroscopy applied to single crystal diamond samples are described in Appendix A. Carbon 1s photoelectron spectroscopic works so far reported for hydrogen-terminated and oxygen-terminated diamond (001) and (111) samples were reviewed placing special attention on surface C 1s components with reference to the key factors. The results showed diversity in C 1s photoelectron spectra so far reported. We had three specific subjects of the study in C 1s XPS; the first is that we have reconfirmed the phenomenon that surface conductive layers resumed when smooth non-doped CVD C(111)-O samples were annealed in vacuum [Diam.Rela.Mate.18(2009)206]. A single C 1s XPS surface component was found for a smooth C(111)-O sample before the vacuum-anneal, which was attributed to surface carbon atoms in C–O–H bonding. The second subject is that dependence of C 1s XPS spectra on surface sensitivity has been measured for all the samples with different surface roughness of C(001)-O, C(111)-O, C(001)-H, and C(111)-H. The results were converted to the energy difference between the Fermi-level (Ef) and valence band maximum (Ev) on the probing depth from the surface. All the samples showed downward bending of Ev toward the surface. For the C(001)-H samples, this was a reconfirmation of previous work [Surf.Sci.604(2010)1148]. For the C(001)-H and C(111)-H samples, various degrees of downward band bending toward surface were observed and analyzed with two-dimensional band simulation. It was concluded that another source of holes such as shallow acceptors is present in a deeper region of the surface in addition to holes very close to surface caused by the charge-transfer-doping. The third subject is that C 1s XPS spectra for superconducting C(111)-O samples showed a lattice distortion of ~9 monolayers near the surface.
AB - Key factors in C 1s photoelectron spectroscopy for realistic samples of single crystal diamonds are remarked. Basic equations for angle-dependent photoelectron spectroscopy applied to single crystal diamond samples are described in Appendix A. Carbon 1s photoelectron spectroscopic works so far reported for hydrogen-terminated and oxygen-terminated diamond (001) and (111) samples were reviewed placing special attention on surface C 1s components with reference to the key factors. The results showed diversity in C 1s photoelectron spectra so far reported. We had three specific subjects of the study in C 1s XPS; the first is that we have reconfirmed the phenomenon that surface conductive layers resumed when smooth non-doped CVD C(111)-O samples were annealed in vacuum [Diam.Rela.Mate.18(2009)206]. A single C 1s XPS surface component was found for a smooth C(111)-O sample before the vacuum-anneal, which was attributed to surface carbon atoms in C–O–H bonding. The second subject is that dependence of C 1s XPS spectra on surface sensitivity has been measured for all the samples with different surface roughness of C(001)-O, C(111)-O, C(001)-H, and C(111)-H. The results were converted to the energy difference between the Fermi-level (Ef) and valence band maximum (Ev) on the probing depth from the surface. All the samples showed downward bending of Ev toward the surface. For the C(001)-H samples, this was a reconfirmation of previous work [Surf.Sci.604(2010)1148]. For the C(001)-H and C(111)-H samples, various degrees of downward band bending toward surface were observed and analyzed with two-dimensional band simulation. It was concluded that another source of holes such as shallow acceptors is present in a deeper region of the surface in addition to holes very close to surface caused by the charge-transfer-doping. The third subject is that C 1s XPS spectra for superconducting C(111)-O samples showed a lattice distortion of ~9 monolayers near the surface.
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U2 - 10.1016/j.diamond.2019.01.017
DO - 10.1016/j.diamond.2019.01.017
M3 - Article
AN - SCOPUS:85061306787
VL - 93
SP - 105
EP - 130
JO - Diamond and Related Materials
JF - Diamond and Related Materials
SN - 0925-9635
ER -