Hussain Z
Department of Electrical and Electronic Engineering, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2BT United Kingdom.
Appl Opt. 1999 Dec 1;38(34):7112-27. doi: 10.1364/ao.38.007112.
Vacuum temperature-dependent ellipsometric studies on WO(3) thin films are reported at a single wavelength, lambda = 0.633 microm, and across a temperature range of 100 < T <or= 453 K. All the measurements were made in an optical cryostat fixed in the sample compartment of the ellipsometer. Experimental results involving reduction and oxidation of WO(3) are discussed in terms of electrochromic characteristics and structural changes, which can be helpful for many and various technological applications. Temperature-dependent drifts in the real part of the refractive index n and extinction coefficient k have been explained by use of a variety of chemical relations and have also been utilized to evaluate their temperature coefficients. Moreover, polaronic excitations between localized states around the Fermi level are put forward to explain the ellipsometric results at or above room temperature, and both polaronic and bipolaronic transitions are proposed for interpreting low-temperature ellipsometric measurements.
报道了在单一波长λ = 0.633微米以及100 < T ≤ 453 K的温度范围内对WO(3)薄膜进行的真空温度相关椭偏研究。所有测量均在固定于椭偏仪样品室的光学低温恒温器中进行。涉及WO(3)还原和氧化的实验结果从电致变色特性和结构变化方面进行了讨论，这对多种技术应用可能有所帮助。利用各种化学关系解释了折射率n的实部和消光系数k随温度的漂移，并用于评估它们的温度系数。此外，提出费米能级周围局域态之间的极化子激发来解释室温及以上温度的椭偏结果，同时提出极化子和双极化子跃迁来解释低温椭偏测量结果。
