## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**\# of TFT**} & \multicolumn{2}{c}{\(\mu_{\text{eff}}\) (cm\({}^{2}\) V\({}^{-1}\) s\({}^{-1}\))} & \multicolumn{2}{c}{\(\Delta V_{\text{th}}\) (V)} \\ \cline{2-5}  & **Before** & **After** & **Before** & **After** \\ \hline
1 & 31.58 & 36.57 & 15.16 & 1.79 \\
2 & 24.79 & 40.55 & 22.33 & 0.98 \\
3 & 15.49 & 23.58 & 19.66 & 0.87 \\
4 & 32.07 & 42.59 & 19.32 & 0.64 \\
5 & 36.99 & 48.52 & 16.32 & 1.04 \\
6 & 51.19 & 75.53 & 20.05 & 0.94 \\
7 & 32.79 & 42.18 & 12.25 & 0.5 \\
8 & 40.93 & 57.62 & 20.09 & 0.54 \\
9 & 31.87 & 37.79 & 16.18 & 0.51 \\
10 & 23.49 & 35.55 & 19.43 & 0.17 \\
11 & 36.83 & 57.22 & 24.37 & 0.72 \\
12 & 33.14 & 41.69 & 13.08 & 0.87 \\
13 & 10.82 & 18.19 & 20.61 & 0.53 \\
14 & 74.57 & 96.67 & 8.58 & 0.15 \\
15 & 32.11 & 46.63 & 14.6 & 0.47 \\ \hline \hline \end{tabular}  
* All the Al\({}_{2}\)O\({}_{3}\) layers were deposited after UV-ozone treatment.  
\end{table} 
Table 1: Comparison of \(\mu_{\text{eff}}\) and \(\Delta V_{\text{th}}\) values of 15 representative Al\({}_{2}\)O\({}_{3}\)-passivated MoS\({}_{2}\) TFTs. 1 In this context, the \(Y\)-function method can be suggested as a proper solution for handling contact resistance in two-terminal systems [8; 34; 35; 36; 37], which underestimates the intrinsic capabilities of active materials. By adopting the mobility reduction coefficient \(\eta\)[34], Equation (1) can be rewritten as  
\[I_{\text{ds}}=\frac{WC_{\text{GI}}}{L}\frac{\mu_{0}}{\left[1+\eta\left(V_{\text{ gs}}-V_{\text{th}}\right)\right]}\left(V_{\text{gs}}-V_{\text{th}}\right)V_{ \text{ds}}\;, \tag{3}\]  
where \(\mu_{0}\) is the intrinsic mobility excluding any contact resistance component. Considering the definition of transconductance, \(g_{\text{m}}\) is also modified using \(\eta\) as follows:  
\[g_{\text{m}}\equiv\frac{\partial I_{\text{ds}}}{\partial V_{\text{gs}}}=\frac {WC_{\text{GI}}}{L}\frac{\mu_{0}}{\left[1+\eta\left(V_{\text{gs}}-V_{\text{th} }\right)\right]^{2}}V_{\text{ds}}\;. \tag{4}\]  
Then, \(\eta\) is eliminated by combining Equations (3) and (4), and the \(Y\)-function can be expressed as  
Figure 4: Transfer characteristics of Al\({}_{2}\)O\({}_{3}\)-passivated MoS\({}_{2}\) TFT under various temperatures ranging from 293 K to 380 K in (**a**) logarithmic and (**b**) linear scales. Insets: temperature-dependent variations of (**a**) \(I_{\text{ds}}\) at \(V_{\text{gs}}\) = 40 V and (**b**) \(V_{\text{th}}\). Figure 5: **(a)** Output characteristics of Al\({}_{2}\)O\({}_{3}\)-passivated MoS\({}_{2}\) TFT under different temperatures of 293 K and 380 K (\(V_{\text{gs}}\) from \(-\)40 to 0 V in 5 V steps); (**b**) comparison of \(\mu_{\text{eff}}\) and the intrinsic carrier mobility \(\mu_{0}\) at various temperatures ranging from 293 K to 380 K. Inset: temperature-dependent variations of the difference between \(\mu_{\text{eff}}\) and \(\mu_{0}\) (\(\Delta\mu\)). Finally, we can extract the intrinsic carrier mobility \(\mu_{0}\) from the slope of the \(Y-V_{\text{gs}}\) plot [8]. Figure 5b presents \(\mu_{\text{eff}}\) and \(\mu_{0}\) of the Al\({}_{2}\)O\({}_{3}\)-passivated MoS\({}_{2}\) TFT at various temperatures, which were calculated from Equations (2) and (5), respectively. At all temperatures, the results showed that (i) all \(\mu_{0}\) values were higher than \(\mu_{\text{eff}}\), indicating the existence of relatively high Schottky barriers and subsequent contact resistances in our devices; and (ii) both \(\mu_{\text{eff}}\) and \(\mu_{0}\) gradually increased with increasing temperature, which can be attributed to reduction of the contact resistance and increased thermionic emission due to high temperature [25; 38]. The inset of Figure 5b presents the temperature-dependent variation of the difference between \(\mu_{\text{eff}}\) and \(\mu_{0}\) (\(\Delta\mu\)), which shows linear response behavior with respect to temperature increase. The details of \(\mu_{\text{eff}}\), \(\mu_{0}\) and \(\Delta\mu\) are provided in Table 2.