212
10 Hetero- and Under-Coordination Coupling
14 12 10 8
6
4
2
0 -2
Smooth-STO
Rough-STO
Rough-Smooth
Intensity
VB(eV)
T
P
533
532
531
530
529
Smooth-STO
Rough-STO
Rough-Smooth
Intensity
BE(eV)
O1s
(a)
(b)
Fig. 10.4 ZPS of the a valence and the b O 1s band for SrTiO 3 with and without defects creation
by 3-keV Ar + beam bombardment [33]. The DOS shows polarization at 1 eV and entrapment at
12 eV. The O 1s band shows entrapment without presence of polarization because its energy is too
far away from the energy of the polarized states. Reprinted with permission from [33]
Table 10.2 Hetero- and under-coordination coupling effect on the energy states of ZnO and SrTiO 3 .
The bulk valley for ZnO should remain constant with reference to large bulk. Energy is in eV unit.
O 1s is insensitive of the polarization effect
ZnO
Polarization (P) Entrapment (T) Bulk valley (B)
8.5–200 nm
Zn 2p 3/2 (eV) –
1022.5
1021
PL (eV)
2.3
1.8
3.5–200 nm
Zn 2p 3/2 (eV) 1020.7
–
1021.8
PL (eV)
1.6
2.0
O-passivated 200 nm Zn 2p 3/2 (eV) 1020.3
–
1021.4
H-passivated 200 nm Zn 2p 3/2 (eV) –
1023.0
1021.2
SrTiO 3
VB (eV)
1
12
4–8
O 1s (eV)
–
531.5
530.4
identify the effect of metal skin nanometerization followed by passivation so clarify
the origin for metal skin functionalization such as Fe thin films [38].
10.4 Summary
A combination of the BOLS-NEP notion and the ZPS distillation has enabled identification of the coupling effect of hetero- and under-coordination on the electron binding energy shift of TiO 2 , ZnO, and SrTiO 3 . Coupling of the irregular-coordination
effect may form efficient means to tune the band gap, carrier life, electroaffinity, and
work function, which determine the catalytic ability, electron and photon emissivity,
hydrophobicity, magnetic property, and toxicity of the undercoordinated compounds.
10 Hetero- and Under-Coordination Coupling
14 12 10 8
6
4
2
0 -2
Smooth-STO
Rough-STO
Rough-Smooth
Intensity
VB(eV)
T
P
533
532
531
530
529
Smooth-STO
Rough-STO
Rough-Smooth
Intensity
BE(eV)
O1s
(a)
(b)
Fig. 10.4 ZPS of the a valence and the b O 1s band for SrTiO 3 with and without defects creation
by 3-keV Ar + beam bombardment [33]. The DOS shows polarization at 1 eV and entrapment at
12 eV. The O 1s band shows entrapment without presence of polarization because its energy is too
far away from the energy of the polarized states. Reprinted with permission from [33]
Table 10.2 Hetero- and under-coordination coupling effect on the energy states of ZnO and SrTiO 3 .
The bulk valley for ZnO should remain constant with reference to large bulk. Energy is in eV unit.
O 1s is insensitive of the polarization effect
ZnO
Polarization (P) Entrapment (T) Bulk valley (B)
8.5–200 nm
Zn 2p 3/2 (eV) –
1022.5
1021
PL (eV)
2.3
1.8
3.5–200 nm
Zn 2p 3/2 (eV) 1020.7
–
1021.8
PL (eV)
1.6
2.0
O-passivated 200 nm Zn 2p 3/2 (eV) 1020.3
–
1021.4
H-passivated 200 nm Zn 2p 3/2 (eV) –
1023.0
1021.2
SrTiO 3
VB (eV)
1
12
4–8
O 1s (eV)
–
531.5
530.4
identify the effect of metal skin nanometerization followed by passivation so clarify
the origin for metal skin functionalization such as Fe thin films [38].
10.4 Summary
A combination of the BOLS-NEP notion and the ZPS distillation has enabled identification of the coupling effect of hetero- and under-coordination on the electron binding energy shift of TiO 2 , ZnO, and SrTiO 3 . Coupling of the irregular-coordination
effect may form efficient means to tune the band gap, carrier life, electroaffinity, and
work function, which determine the catalytic ability, electron and photon emissivity,
hydrophobicity, magnetic property, and toxicity of the undercoordinated compounds.