本論文採用溶膠-凝膠法搭配旋轉塗佈技術，在玻璃基板上成功製備出摻0~4 at.% 鎵(GZO)、摻0~1 at.%鈦(TZO)與共同摻入0.0 ~1.0 at.%鈦和2 at.%鎵之氧化鋅(Ti, Ga co-doped zinc oxides， TGZO)透明氧化物薄膜，進而研究薄膜之微結構與光電特性。薄膜的表面與橫斷面形貌藉由SEM觀察，結果顯示:純氧化鋅薄膜隨著摻鎵、摻鈦及共摻都皆有晶粒細化現象。晶體結構由XRD分析得知:薄膜皆為六方晶系纖維鋅礦結構，以C軸優選方向，可依Scherrer公式估計其晶粒大小，與SEM觀察印證。鈦、鎵共摻薄膜之晶粒，隨摻鈦量由0增加至1 at.%，其尺寸由16減小至13nm，稍有細化現象。Raman分析佐證出氧化鋅薄膜摻雜造成晶粒細化現象。AFM分析顯示:鈦、鎵共摻薄膜中摻鈦濃度由0增至1.0% 會降低其表面粗糙度。XPS分析鎵、鈦共摻薄膜，顯示所摻雜的鎵之化學狀態為Ga2O3(Ga3+)；而及所摻雜的鈦則為TiO2(Ti4+)。薄膜光學性質經UV-Vis光譜儀進行分析，結果得知: 摻鎵薄膜平均透光率約82%、摻鈦者為89%，共摻者約88%；薄膜之電阻率則用四點探針量測、載子濃度和載子移動率則由霍爾分析儀鑑定，結果顯示: 氧化鋅摻2 at.%鎵之有一最低電阻率(約13 Ω cm)、摻0.5 at.%鈦之薄膜有一最低電阻率(約59 Ω cm)，共摻2 at.%鎵與1 at.% 鈦薄膜則其透光率增高至91%而電阻率則降至7.35 Ω cm。 Transparent conductive zinc oxide (ZnO) thin films singly doped with 0.0~4.0 at.% Ga (GZO), 0.0~4.0 at.% Ti (TZO) and co-doped 2 at.% Ga with 0.25, 0.50, 0.75 and 1.00 at.% Ti were prepared on glass substrates by sol-gel method by means of spin-coating. The microstructure, optical, and electrical properties of GZO, TZO and TGZO films were investigated. Through examination by scanning electron microscope (SEM), we found that the surface and cross-sectional morphology indicated grain refinement in the doped films in comparison with the pure ZnO. Analysis of X-ray diffraction (XRD) revealed all the films belonged to wurtzite structure preferred along c-axis and their grain size estimated by Scherrer’s formula was consistent with that observed by SEM. Avereage grain size in TGZO decreased form 16 to 13 nm with increasing Ti-dopant from 0 to 1 at.%. This grain refinement was confirmed with the Raman spectra. Measurement by atomic force microscope indicated that TGZO decreased the surface roughnss with increasing Ti-content from 0 to 1.0 at.%. X-ray photoelectron spectroscopy (XPS) spectra of the TGZO films showed that the binding energy located at 1118.5 eV responsible for Ga3+and that located at 458.7 eV responsible for Ti4+. The electrical properties such as resistivity, carrier concentration, and Hall mobility were detected by four-point probe and Hall measurements. Optical transmittance measured by UV-Vis spectrophotometer indicated 82% for GZO, 89% for TZO and 88% for TGZO. The resistivity was measured at 13 Ω cm for GZO doped with 2 at.%Ga, at 59 Ω cm for TZO doped with 0.5 at.%Ti, at 7.35 Ω cm for T1.00G2.0ZO co-doped 2 at.% Ga with 1 at.% Ti.
