# CZTSe-Based Solar Cell Performance Improvement Using the CSLO Technique
## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Reference** & **Fill Factor (\%)** & **Efficiency (\%)** \\ \hline Conventional CZTSe solar cell (Case 1) & 66.79 & 18.86 \\ Case 3 & 79.55 & 32.6 \\
[33] & 38.2 & 4.35 \\
[34] & 76.46 & 17.04 \\
[35] & \(50.8\pm 4.1\) & \(5.5\pm 0.6\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Comparation results of the proposed solar cell with previously published solar cells. Figure 4: Efficiency variation versus carrier lifetime. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Solar Cell** & **Fill Factor (\%)** & **Efficiency (\%)** \\ \hline hybrid structure (CZTSe and CZTS) & 66 & 41.54 \\ hybrid structure (CZTSe and Cu\({}_{2}\)ZnSiSe\({}_{4}\)) & 42 & 33.61 \\ hybrid structure (CZTSe and Cu\({}_{2}\)ZnGeSe\({}_{4}\)) & 54.82 & 50.112 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparation results of hybrid solar cells. Moreover, by decreasing the absorber layer, the optical properties were decreased. As illustrated in Figure 5b, the EQE of the solar cell was decreased in lower wavelengths for case 1. Likewise, the electrical properties of case 1 declined by decreasing the width of the absorber layer, as demonstrated in Figure 5b. Thus, by selecting the optimum width of the absorber layer, more advantages will be obtained. In this regard, over the entire simulation, the optimum value of 2 microns was chosen for the absorber layer for the different cases. Furthermore, another important parameter is the total effect density of the solar cell. Therefore, the effect densities of the p+pn junction and the ZnO/ITO layers must be selected precisely. Due to this, the effect density of the p+pn junction was chosen, as depicted in Figure 5b. Thus, the effect density of the p+pn junction is decreased by increasing the width of the absorber layer. Figure 5: (**a**) Electrical properties versus absorber thickness. (**b**) EQE versus absorber thickness for Case 1. Table 1, to be consistent over the entire simulation, because the main of the purpose of this article was to study the effects of the proposed CSLO technique in carrier-generating layers. Furthermore, the impact of ZnO/ITO defect density was investigated. As shown in Figure 6, by changing the effect density from 1 \(\times\) 10\({}^{16}\) cm\({}^{-3}\) to 1 \(\times\) 10\({}^{19}\) cm\({}^{-3}\) for case 1, the efficiency and fill factor (%) decreased. Regarding this, the specifications of the layers must be considered in the simulation. Modeling CZTSe solar cells in a simulated environment as presented here is critical for data analysis and real fabrication behavior projection. This optimization is beneficial for the commercial use of CZTSe solar cell technology. Various electrochemical and fabrication strategies are currently being researched in order to achieve layer specifications similar to those in Table 2. There are current results that suggest that the Pulsed laser deposition [41], Spray pyrolysis [42], Vacuum deposition method [43; 44], Magnetron sputtering [45], and sol-gel [46; 47] methods could be of use for achieving two divided absorber layers like those simulated by the CSLO technique.