Development of amorphous transparent conductive oxide films and their applications to transparent electrodes

采用同步溅射法制备了In_2O_3-ZnO透明导电薄膜。随着δ=Zn/(Zn+In)比值的增大，出现非晶相和同源相。讨论了这些薄膜的载流子生成机理。原生氧缺陷是In_2O_3-ZnO薄膜的主要供体。在δ=Zn/(Zn+In)的窄范围内，获得了2 ~ 4×10^<-4> Ω cm的低电阻率。2 wt% al_2o_3掺杂使电阻率降低至1.5 ~ 2.1×10^<-4>Ωcm。当掺杂3wt %和4wt % Al_2O_3时，由于载流子浓度在δ=0.3-0.6处增加，非晶相δ范围较宽，膜电阻率为2-4×10^<-4>。另一方面，在同源的Zn_kIn_2O_<k+3>晶体膜中掺杂的Al_2O_3没有作为给体杂质。在Al_2O_3含量高于2 wt%时，非晶膜的光学带隙能量与Al_2O_3含量成正比，归因于Al_2O_3的晶格畸变。在还原性气体流动下进行后退火，可以有效地改善非晶膜的不均匀性。用相同的方法制备了ZnO-SnO_2体系薄膜，其中ZnO和SnO_2:Sb （Sb_2O_5掺杂3wt%）靶相互面对。沉积膜的成分随电流比δ的变化而变化。在Ts=150℃时，出现了0.47【小于等于】δ【小于等于】0.80 （Zn/(Sn+Zn)=0.28 ~ 0.76）的非晶态透明膜；在Ts=250℃时，出现了0.33【小于等于】δ【小于等于】0.73 （Zn/(Sn+Zn)=0.32 ~ 0.66）的非晶态透明膜。δ= 0.62(锌/ (Sn +锌)= 1/2)或6 = 0.73(锌/ (Sn +锌)= 2/3)和任何其他比as-deposited电影中我们可以获得水晶ZnSnO_3和Zn_2SnO_4无定形电影作为形式的存在(ZnSnO_3)值(SnO_2) _ < 1 - x > 0.5的【小于或等于】【小于或等于】δ0.62(0【小于或等于】【小于或等于】δ)和(ZnSnO_3) _ < 1 y >(氧化锌)_y吗,在一系列0.62【小于或等于】【小于或等于】δ0.73 (0 y【小于或等于】【小于或等于】0.5)。在δ=0.50 （Zn/(Sn+Zn)=0.33）、Ts=250℃时，沉积的非晶薄膜的最小电阻率为3.6×10^<-2> Ωcm。少

We deposited In_2O_3-ZnO transparent conductive films by simultaneous sputtering of ZnO and In_2O_3 ceramic targets. Amorphous and homologous phases appeared with increasing δ=Zn/(Zn+In) ratios. Carrier generation mechanism was discussed for these films. Native oxygen defects are the primary donors for the In_2O_3-ZnO films. Then the low resistivities of 2〜4×10^<-4> Ω cm were attained within a narrow range of δ=Zn/(Zn+In) in the amorphous phase film. 2 wt% Al_2O_3-doping decreased the resistivity to 1.5〜2.1×10^<-4>Ωcm. At doping of 3 wt% and 4 wt% Al_2O_3, film resistivities of 2-4×10^<-4> were attained for a relatively wide range of δ in the amorphous phase due to an increase in carrier concentration at δ=0.3-0.6. On the other hand, Al_2O_3 doped in the homologous Zn_kIn_2O_<k+3> crystalline films did not act as donor impurities. The optical bandgap energy for the films deposited above 2 wt% Al_2O_3 for amorphous film was proportional to Al_2O_3 content, ascribed to lattice distortion … More by Al_2O_3. Post annealing under the reductive gas flow was effective on improving unevenness of the amorphous films.Thin films of ZnO-SnO_2 system were also deposited by the same method, where ZnO and SnO_2:Sb (Sb_2O_5 3wt% doped) targets were faced each other. Compositions in as-deposited films were changed with the current ratio δ. Amorphous transparent films appeared in a range of 0.47【less than or equal】δ【less than or equal】0.80 (Zn/(Sn+Zn)=0.28-0.76) at Ts=150℃, in a range of 0.33【less than or equal】δ【less than or equal】0.73 (Zn/(Sn+Zn)=0.32-0.66) at Ts=250℃. At δ=0.62 (Zn/(Sn+Zn)=1/2) or 6=0.73 (Zn/(Sn+Zn)=2/3) and any other ratio in as-deposited films we could obtain neither crystalline ZnSnO_3 nor Zn_2SnO_4 Amorphous films would exist as forms of (ZnSnO_3)_x(SnO_2)_<1-x> in a range of 0.5【less than or equal】δ【less than or equal】0.62 (0【less than or equal】δ【less than or equal】) and (ZnSnO_3)_<1-y>(ZnO)_y, in a range of 0.62【less than or equal】δ【less than or equal】0.73 (0【less than or equal】y【less than or equal】0.5). Minimum resistivity of amorphous films deposited was 3.6×10^<-2> Ωcm at δ=0.50 (Zn/(Sn+Zn)=0.33), Ts=250℃. Less