Surface segregation of W doped in ZnO thin films

被引：9

作者：

Suzuki, T. T. ^{[1
]}

Adachi, Y. ^{[1
]}

Saito, N. ^{[1
]}

Hashiguchi, M. ^{[1
]}

Sakaguchi, I. ^{[1
]}

Ohashi, N. ^{[1
]}

Hishita, S. ^{[1
]}

机构：

[1] Natl Inst Mat Sci, Tsukuba, Ibaraki 3050044, Japan

来源：

SURFACE SCIENCE | 2014年 / 625卷

关键词：

Surface segregation; Ion scattering spectroscopy; Tungsten; Zinc oxide; PHOTOCATALYTIC DEGRADATION; COMPOSITE POWDERS; ION-SCATTERING; TUNGSTEN; SAPPHIRE; GROWTH; WO3; POLARITY; DRIVEN; DYE;

D O I：

10.1016/j.susc.2014.02.014

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We observed surface segregation of W (0.05-4 mol%) doped in ZnO films by annealing above 900 K. The segregation coefficient was related to the crystal quality of the film, where slower segregation occurs in higher-quality crystalline films. Using low-energy He+ ion scattering spectroscopy for structure analysis, we found that the W-ZnO surface terminates with an O-layer, and W is located in a substitutional site of Zn at the second surface layer as a consequence of segregation. On the other hand, we observed no indication that W occupies certain sites in the ZnO lattice at the subsurface. Ultraviolet photoelectron spectroscopy (He I) on the W-segregated ZnO surface indicates that W is hexavalent at the Zn site. The segregation of the W atom is likely accompanied by two Zn vacancies. Ion beam mixing followed by annealing of the ZnO surface deposited with W provides a surface electronic structure similar to that of W-segregated ZnO. (C) 2014 Elsevier B.V. All rights reserved.

引用

页码：1 / 6

页数：6