Excited state dynamics and semiconductor-to-metallic phase transition of VO2 thin film

被引：27

作者：

Liu, H ^{[1
]}

Vasquez, O ^{[1
]}

Santiago, VR ^{[1
]}

Díaz, L ^{[1
]}

Fernandez, FE ^{[1
]}

机构：

[1] Univ Puerto Rico, Dept Phys, Mayaguez, PR 00681 USA

来源：

JOURNAL OF LUMINESCENCE | 2004年 / 108卷 / 1-4期

关键词：

Li/VO2; phase transition; DFWM; thin film; excited state;

D O I：

10.1016/j.jlumin.2004.01.050

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

VO2 thin films deposited on fused-quartz substrates were prepared by a pulsed laser deposition technique. Vanadium dioxide shows an ultrafast, passive phase transition (PT) from a monoclinic semiconductor phase to a metallic tetragonal rutile structure when the sample temperature is above 68degreesC. The fast PT can also be optically induced by laser excitation. In this paper, we report the optical properties of prepared thin films by absorption and photoluminescence (PL) measurements. In addition, a degenerate-four-wave-mixing measurement was also conducted using a 30 ps YAG pulsed laser operated at 532 nm. It is the first time, to our knowledge, that a large polarizability and relatively slow nanosecond excited state dynamical processes have been identified in VO2. The polarizability is found to be similar to 300 times greater than the chi((3)) value of a CS2 reference. The mechanism for slow process is believed to be associated with the structural change. (C) 2004 Elsevier B.V. All rights reserved.

引用

页码：233 / 238

页数：6

共 15 条

[1] STUDIES ON VANADIUM OXIDES .2. THE CRYSTAL STRUCTURE OF VANADIUM DIOXIDE [J].