Department of Mechanical Engineering, University of Texas at El Paso, El Paso, Texas 79968, USA.
ACS Appl Mater Interfaces. 2010 Sep;2(9):2623-8. doi: 10.1021/am1004514.
Nanocrystalline WO3 films were grown by reactive magnetron sputter-deposition by varying the substrate temperature in the range of 303(RT)-673 K. The structure and electrical transport properties of WO3 films were evaluated using X-ray diffraction and dc electrical conductivity measurements. The effect of ultramicrostructure and grain-size was significant on the electrical properties of WO3 films. DC conductivity variation of the WO3 films measured in the temperature range of 120-300 K reveals their semiconducting nature. The temperature dependent electrical conductivity curves exhibit two distinct regions indicative of two different types of electrical transport mechanisms. Analysis of the conductivity indicates that the small polaron and variable-range-hopping mechanisms are operative in 180-300 K and 120-180 K temperature regions, respectively. The density of localized states at the Fermi level, N(EF), has been calculated and it was found to be ∼1×10(19) eV(-1) cm(-3) for all the films.
采用反应磁控溅射沉积法，通过改变基底温度在 303（室温）-673 K 的范围内，制备了纳米晶 WO3 薄膜。通过 X 射线衍射和直流电导率测量对 WO3 薄膜的结构和电输运性质进行了评估。WO3 薄膜的超微结构和晶粒尺寸对其电性能有显著影响。在 120-300 K 的温度范围内测量的 WO3 薄膜的直流电导率变化表明其具有半导体性质。电导率随温度的变化曲线呈现出两个不同的区域，表明存在两种不同类型的电输运机制。对电导率的分析表明，在 180-300 K 和 120-180 K 的温度区域内，分别存在小极化子和变程跳跃机制。费米能级处的局域态密度 N(EF) 已被计算出来，所有薄膜的 N(EF) 值均约为 1×10(19) eV(-1) cm(-3)。
