Nb掺杂ZnO透明导电薄膜的结构以及光电性能研究

Study on the Structure,Optical and Electrical Properties of Nb Doped ZnO Transparent Conductive Thin Films

采用直流磁控溅射法在玻璃衬底上制备了高质量的Nb掺杂ZnO(NZO)透明导电薄膜。为了研究薄膜厚度对薄膜性质的影响,制备了五个厚度分别为239 nm,355 nm,489 nm,575 nm和679 nm的样品。XRD结果表明,ZnO∶Nb薄膜是具有六角纤锌矿结构的多晶薄膜,并且具有垂直于衬底的c轴择优取向。随着膜厚的增加,薄膜的结晶质量明显提高。当厚度从239 nm增加到489 nm时,平均晶粒尺寸从19.7 nm增加到24.7 nm,薄膜的电阻率持续减小;当厚度进一步增加时,晶粒尺寸略有减小,电阻率有所增加。本实验获得的最低电阻率为4.896×10-4Ω·cm。随膜厚的增加,光学带隙先增大后减小。所有薄膜在可见光区域的平均透过率均超过88.3%。

Highly conducting and transparent niobium doped zinc oxide （NZO） thin films had been deposited by DC magnetron sputtering method on glass substrates. Five samples with thickness of 239 nm, 355 nm, 489 nm,575 nm and 679 nm are used for the analysis of film thickness effect. XRD studies show that the ZnO： Nb films are polycrystalline with the hexagonal structure and have preferred orientation with the c axis perpendicular to the substrates. The crystallinity of the films improved significantly as the thickness increasing. As the thickness increasing from 239 nm to 489 nm, the mean crystallite size increases from 19. 7 nm to 24. 7 nm and the resistivity decreases continuously. As the thickness increasing further, the crystallite size shows a little decrease and the resistivity increases a little. The lowest resistivity obtained is 4. 896 × 10^-4 Ω· cm in this experiment. The optical band gap initially increases and then decreases when the film thickness increases. All the films present a transmittance of above 88.3% in the wavelength range of the visible spectrum.