## 3 Results and Discussion  
Table 1 shows the power combinations used to prepare the Zr-AZTO. The variate of Sample A and Sample B is the discharge power of AZTO, which is 120 W and 100 W. The variate of Sample B, C, D, and E is the discharge power of ZrO\({}_{2}\) target, which is 15 W, 25 W, 35 W, and 45 W.  
Figure 1 shows the Zr-AZTO XPS of Zr 3d, indicating that there are two peaks at 182 eV (Zr 3d\({}_{5/2}\)) and 185 eV (Zr 3d\({}_{3/2}\)), and the element zirconium is present in the form of ZrO\({}_{2}\)[13; 14]. From Sample A to Sample E, the Zr content respectively is 0.34 \(\pm\) 0.01 at.%, 0.63 \(\pm\) 0.01 at.%, 1.00 \(\pm\) 0.01 at.%, \begin{table}
\begin{tabular}{c c c c c c} \hline  & **Sample A** & **Sample B** & **Sample C** & **Sample D** & **Sample E** \\ \hline Power of ZrO\({}_{2}\) (W) & 15 & 15 & 25 & 35 & 45 \\ Power of AZTO (W) & 120 & 100 & 100 & 100 & 100 \\ \hline \end{tabular}
\end{table} 
Table 1: The discharge power of Zr-doped aluminum-zinc-tin oxide (Zr-AZTO) fabrication. \(1.78\pm 0.01\) at.%, and \(2.79\pm 0.01\) at.%. With the discharge power of AZTO target decreasing, Zr content increases from \(0.34\pm 0.01\) at.% to \(0.63\pm 0.01\) at.%. Figure 2a shows the two peaks merging together because of the low Zr content of Sample A. With the discharge power of ZrO\({}_{2}\) target increasing, Zr content increases from \(0.63\pm 0.01\) at.% to \(2.79\pm 0.01\) at.%, and the discharge power of ZrO\({}_{2}\) is the main factor of thin film Zr content. Table 2 is the peaks table of the elements used in Zr-AZTO films (except for Zr). For the Al element, the peak of Al 2p\({}_{3/2}\) is around 73.60 eV, which indicates the Al element is present in the form of Al\({}_{2}\)O\({}_{3}\)[15]. For Sn and Zn element, the peaks of Sn 3d\({}_{5/2}\) and Zn 2p\({}_{3/2}\) are about 486.60 eV and 1021.60 eV, which means the Sn and Zn element in the films are present in form of SnO\({}_{2}\) and ZnO [16; 17]. Figure 3 is the O 1 s spectra of Zr-AZTO of different power combinations. The O 1 s peak can be divided into three sub-peaks: (1) the M-O-M peak at 530 eV represents the O\({}^{2-}\) binding with Zr, \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Sample A** & **Sample B** & **Sample C** & **Sample D** & **Sample E** \\ \hline Peak of Al 2p\({}_{3/2}\) (eV) & 73.53 & 73.55 & 73.60 & 73.60 & 73.59 \\ Peak of Sn 3d\({}_{5/2}\) (eV) & 486.60 & 486.60 & 486.60 & 486.58 & 486.59 \\ Peak of Zn 2p\({}_{3/2}\) (eV) & 1021.61 & 1021.62 & 1021.63 & 1021.59 & 1021.59 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The peaks table of element in Zr-AZTO films. Figure 1: Zr-AZTO XPS of different co-sputter power: (**a**) 15 W ZrO\({}_{2}\) target; (**b**) 100 W AZTO target. Figure 2: The image of practical device (**a**) and the schematic diagram of bottom gate Zr-AZTO TFT structure (**b**). Al, Sn, Zn; (2) the Vo peak at 531 eV represents the oxygen vacancy; (3) the M-O-R peak at 532 eV represents the weakly bond like H\({}_{2}\)O, -CO\({}_{3}\) and -OH [18]. The proportion of sub-peak area can indicate the different bond species content. Calculating with S\({}_{\text{vo}}\)/S\({}_{\text{all}}\) ratio of Sample A and Sample B, it is found that the oxygen vacancy of Sample A-E is 17.3 \(\pm\) 0.8%, 19.0 \(\pm\) 0.1%, 16.0 \(\pm\) 0.7%, 15.4 \(\pm\) 0.6%, and 14.1 \(\pm\) 0.1%. With the discharge power of AZTO increasing from 100 W to 120 W, the oxygen vacancy decreases from 17.3 \(\pm\) 0.8% to 19.0 \(\pm\) 0.1% and with the discharge power of ZrO\({}_{2}\) increasing from 15 W to 45 W, the content of oxygen vacancy decreases from 19.0 \(\pm\) 0.1% to 14.1 \(\pm\) 0.1%. Since it is known that the carriers of oxide semiconductors are related to oxygen vacancy, the Sample B has a highest carrier density [19]. Figure 3: O 1 s XPS spectrum of Zr-AZTO films: (**a**) Sample A; (**b**) Sample B; (**c**) Sample C; (**d**) Sample D; (**e**) Sample E.  
Figure 4 shows the transmittance of the Zr-AZTO thin films of different groups measured by UV-2600.