瞬时蒸发法制备Bi薄膜的微观结构及电输运性能

Microstructure and Electrical Transport Properties of Bismuth thin Films Prepared by Flash Evaporation

用瞬时蒸发法在加热到453K的玻璃基体上沉积出了厚度在40-160nm的多晶Bi纳米薄膜。用X射线衍射(XRD)、场发射扫描电子显微术(FE-SEM)分析了薄膜的相结构和表面形貌。在300-350K研究了薄膜厚度与电阻率的关系,随着薄膜厚度增加,电阻率并不是单调减小;随着温度增加,电阻率减小。温度在300K时,Bi薄膜的电阻率在0.36-0.46mΩ·cm之间变化。随着薄膜厚度的增加,Seebeck系数增加。电子浓度、迁移率与薄膜厚度的关系表明薄膜的电输运性能随薄膜厚度的变化而波动。

Polycrystalline Bi thin films with thickness in the range of 40-160 nm were successfully deposited on glass substrates at 453K by flash evaporation method. XRD and FE-SEM were performed to characterize their structure and surface morphology respectively. The preferred orientation （012） is present in all the thin films. FESEM image shows that the deposited Bi thin films are very compact. It is observed that the grains are well crystallized and homogeneously distributed. Electrical resistivity was carried out in the temperature range 300-350K. Electrical resistivity of the thin films does not show a monotonic decrease with increasing thickness. The values of electrical resistivity are in range of 0.36-0. 46mΩ cm at 300K. Seebeck coefficients of Bi thin films increase with increasing thickness. Electron concentration and mobility were measured at 300K. A distinctly fluctuant behavior has been observed for the electrical transport properties of Bi thin films.