Effects of Hydrogen on the Optical and Electrical Characteristics of the Sputter-Deposited Al2O3-Doped ZnO Thin Films

摘要

In this study, AZO thin films were deposited on glass by using a 98 mol% ZnO + 1 mol% Al2O3(AZO, Zn : Al = 98 : 2) ceramic target and a r.f. magnetron sputtering system. At first, the effects of different H2flow rates (H2/(H2+ Ar) = 0%~9.09%, abbreviated as H2-deposited AZO thin films, deposition temperature was 200°C) added during the deposition process on the physical and electrical properties of AZO thin films were investigated. The optical transmittance at 400 nm~700 nm is more than 80% for all AZO thin films regardless of H2flow rate and the transparency ratio decreased as the H2flow rate increased. The Burstein-Moss shift effect was used to prove that the defects of AZO thin films decreased with increasing H2flow rate. Also, the 2% H2-deposited AZO thin films were also treated by the H2plasma at room temperature for 60 min (plasma-treated AZO thin films). The value variations in the optical band gap (Eg) values of the H2-deposited and plasma-treated AZO thin films were evaluated from the plots ofαhν2=c(hν−Eg), and theEgvalues increased with increasing H2flow rate. TheEgvalues also increased as the H2-plasma process was used to treat on the H2-deposited Al2O3-doped ZnO (AZO) thin films.