厚度对室温沉积ZnO:Al薄膜光电特性的影响

利用直流磁控溅射法, 在室温玻璃衬底上制备了具有良好附着性的多晶ZnO∶ Al(ZAO)薄膜. 比较了室温下获得的薄膜与衬底加热条件下所得薄膜的结晶程度, 研究了厚度对室温条件下制备的ZAO薄膜表面形貌、电学性能及紫外-可见-近红外光区透光性的影响. 结果表明, 室温条件下制备的ZAO薄膜也具有(002)面择优取向, 随着膜厚的增加薄膜晶粒化程度提高, 载流子浓度和迁移率增大, 电阻率下降, 薄膜在紫外光区的吸收边发生红移, 在可见光区的平均透过率降低, 在近红外光区的透过率随厚度的增加而减小. 厚度为1200 nm的ZAO薄膜具有最佳光电综合性能, 其电阻率为7.315×10~(-4) Ω·cm, 方块电阻为6.1 Ω/□, 可见光区平均透过率达到82%, 波长为550 nm处的透过率为87%.

Influence of Thickness on Optical and Electrical Properties of ZnO:Al Thin Films by DC-Magnetron Sputtered at Room Temperature

Without intentionally heating the substrates, polycrystalline aluminum doped zinc oxide (ZnO∶ Al, ZAO) thin films with good adhesion were prepared on glass substrates by DC magnetron sputtering. The structure and crystallization of the films were compared with the one deposited with substrate heating. The dependence of morphological, electrical and optical properties on film thickness was systematically investigated. The results showed that highly preferred (002) orientation ZAO film was produced at room temperature. The degree of crystallinity was improved, carrier concentration and mobility increased while the resistivity decreased with the film thickness growing. A "red-shift" was observed at the absorption edge, and the average transmittance in the visible and near-infrared range decreased with the increase of film thickness. ZAO film with a thickness of 1200 nm had the lowest sheet resistance of 6.1 Ω/□ and a resistivity of 7.315×10~(-4) Ω·cm. Its average optical transmittance in visible range and the transmittance at 550nm was 82% and 87%, respectively.