Structural influences on the photoelectric properties of TiO2

被引：14

作者：

Damm, C

Müller, FW

Israel, G

Gablenz, S

Abicht, HP

机构：

[1] Univ Halle Wittenberg, Inst Organ Chem, D-06217 Merseburg, Germany

[2] Inst Anorgan Chem, D-06120 Halle An Der Saale, Germany

来源：

DYES AND PIGMENTS | 2003年 / 56卷 / 02期

关键词：

photo-EMF; TiO2; structure; coating;

D O I：

10.1016/S0143-7208(02)00114-6

中图分类号：

O69 [应用化学];

学科分类号：

081704 ;

摘要：

The Influence of crystal structure and surface coating-on the photoelectric properties of TiO2 pigments was studied using the transient photo-EMF. Amorphous TiO2 did not show any photo-EMF signal showing that it is not a photo conductor. The-crystalline TiO2 modifications, anatase and rutile, behave like n-type photoconductors. In comparison to rutile, the maximum photo-EMF of anatase was significantly larger.-While the photo-EMF signal of the rutile changed under repetitive laser flash exposure, the signal of, anatase did not depend on number of flashes. This shows that only rutile contains a small amount of very deep traps. So in rutile-a small part of charge carriers live longer than in anatase. Coating anatase with the photoelectrically inert Ba(OH)(2)*nH(2)O or BaCO3 reduced the photo-EMF signal. The epitaxial coating of rutile with SiO2 and Al2O3 resulted in a complex photo-EMF signal that displayed two negative maximum voltages. Such behaviour suggests that heterojunctions may exist in the substrate. (C) 2002 Published by Elsevier Science Ltd.

引用

页码：151 / 157

页数：7

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