An angular dependent X-ray photoemission study of Indium-tin-oxide surfaces

2002 ◽  
Vol 747 ◽  
Author(s):  
H. H. Fong ◽  
W. J. Song ◽  
S. K. So
Keyword(s):  
Work Function ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Surface Band ◽  
Band Bending ◽  
X Ray ◽  
Plasma Treatments ◽  
Photoemission Study ◽  
Uv Ozone

ABSTRACTThe surface properties of indium-tin-oxide (ITO) thin films treated by UV ozone or plasma were analyzed by angular dependent X-ray photoelectron spectroscopy (ADXPS) and by ultraviolet photoemission (UPS). The chemical composition, chemical states and the work function of the ITO surfaces were deduced. Our analysis indicate that ITO surface is Sn-rich. Both UV ozone and O-plasma treatments are most effective in removing surface hydrocarbon. Among all treatments, O-plasma treated surface achieved the highest work function of 4.4eV, whereas argon ion sputtered surface had the lowest work function of 3.9eV. Both O-plasma and UV ozone treatments increase the surface oxygen concentration. It is proposed that O2-ions diffuse into ITO. The diffusion length is about 50Å as deduced from ADXPS. The stoichiometry of the surface is the major factor in controlling the surface work function of ITO. A surface band bending model is proposed to account for the change of work function due to “oxidized” ITO surface after UV-ozone or oxygen plasma treatments.

Surface Electronic Structure of Nitric-oxide-treated Indium Tin Oxide

2003 ◽  
Vol 796 ◽  
Author(s):  
Hu Jianqiao ◽  
Pan Jisheng ◽  
Furong Zhu ◽  
Gong Hao
Keyword(s):  
Nitric Oxide ◽  
Binding Energy ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Surface Region ◽  
Valence Band Maximum ◽  
Surface Band ◽  
Band Bending ◽  
Surface Electronic Structure

ABSTRACTThe surface electronic properties of the nitric oxide (NO) treated indium tin oxide (ITO) are examined in-situ by a four-point probe and X-ray photoelectron spectroscopy (XPS). The XPS N1s peak emerged at a high binding energy of 404 eV indicating that NO is reactive with ITO. NO adsorption induces an increase of film sheet resistance, arising from an oxygen rich layer near the ITO surface region, with approximately 2.5 nm thick. This implies that the interaction of NO with ITO is occurred around surface region. Valence band maximum measured for NO-absorbed ITO was shifted to the low binding energy side. This is related to the upward surface band bending.

Angle dependent X-ray photoemission study on UV-ozone treatments of indium tin oxide

2001 ◽  
Vol 177 (3) ◽  
pp. 158-164 ◽  
Author(s):  
Weijie Song ◽  
S.K So ◽  
Daoyuan Wang ◽  
Yong Qiu ◽  
Lili Cao
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
X Ray ◽  
Photoemission Study ◽  
Uv Ozone ◽  
Ozone Treatments

Evidence of nitric-oxide-induced surface band bending of indium tin oxide

2004 ◽  
Vol 95 (11) ◽  
pp. 6273-6276 ◽  
Author(s):  
Jianqiao Hu ◽  
Jisheng Pan ◽  
Furong Zhu ◽  
Hao Gong
Keyword(s):  
Nitric Oxide ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Surface Band ◽  
Band Bending

X-ray photoelectron spectroscopy studies of indium tin oxide nanocrystalline powder

2005 ◽  
Vol 54 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Bagas Pujilaksono ◽  
Uta Klement ◽  
Lars Nyborg ◽  
Urban Jelvestam ◽  
Sven Hill ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Nanocrystalline Powder ◽  
X Ray ◽  
Spectroscopy Studies

Role of Surfaces and Interfaces for the Electronic Properties of Conducting Oxides

2001 ◽  
Vol 666 ◽  
Author(s):  
Andreas Klein
Keyword(s):  
Work Function ◽  
Electronic Properties ◽  
Photoelectron Spectroscopy ◽  
Band Alignment ◽  
Surface Band ◽  
Band Bending ◽  
Conducting Oxides ◽  
Degenerate Semiconductors ◽  
Surfaces And Interfaces

ABSTRACTTransparent conductive oxides (TCOs) are generally considered as degenerate semiconductors doped intrinsically by oxygen vacancies and by intentionally added dopants. For some applications a high work function is required in addition to high conductivity and it is desired to tune both properties independently. To increase the work function, the distance between the Fermi energy and the vacuum level must increase, which can be realized either by electronic surface dipoles or by space charge layers. Photoelectron spectroscopy data of in-situ prepared samples clearly show that highly doped TCOs can show surface band bending of the order of 1 eV. It is further shown that the band alignment at heterointerfaces between TCOs and other materials, which are crucial for many devices, are also affected by such band bending. The origin of the band bending, which seems to be general to all TCOs, depends on TCO thin film and surface processing conditions. The implication of surface band bending on the electronic properties of thin films and interfaces are discussed.

Nanofunctionalized Phosphor Particles for Advanced Display Applications

2001 ◽  
Author(s):  
Michael Ollinger ◽  
Valentin Craciun ◽  
Rajiv Singh
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Degradation Rate ◽  
Binding Energies ◽  
Xps Analysis ◽  
Surface Chemical ◽  
Chemical Changes ◽  
X Ray ◽  
Two Peaks

Abstract Cathodoluminescence (CL) degradation measurements showed that by applying a nano meter scale indium tin oxide (ITO) coating on micron sized ZnS:Ag particulates the degradation lifetime was dramatically improved. X-ray photoelectron spectroscopy (XPS) analysis showed that the Zn 2p3/2 and S 2p3/2 peaks of the degraded ZnS:Ag were shifted to higher binding energies, which correspond to oxidized elements, with respect to those found for as-received ZnS:Ag. The XPS analysis for the ITO coated ZnS:Ag showed a broadening of the Zn 2p3/2 and S 2p3/2 peaks, which were a convolution of two peaks. In this case, the Zn 2p3/2 and S 2p3/2 peaks corresponding to ZnS were still present together with a small shoulder corresponding to the oxidized elements. This difference in the XPS shows that the ITO coating reduced the degradation rate by slowing the surface chemical changes on the ZnS:Ag.

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