# Preparation of Hybrid Molybdenum Disulfide/Single Wall Carbon Nanotube-n-Type Silicon Solar Cells
## 4 Conclusions  
The addition of MoS\({}_{2}\) flakes was shown to improve the performance of SWCNT/Si heterojunction solar cells. Cells with two different structures were explored; namely cells where the SWCNTs and MoS\({}_{2}\) flakes were mixed together in one layer or cells where the MOS\({}_{2}\) layers was deposited first followed by the SWCNT layer. The cells with a MoS\({}_{2}\) layer covered by the SWCNTs gave the best performance. The improvement is significant with increases in efficiencies from 6.83% to 10.04% observed. The increase in device efficiency can be largely attributed to significant increases in fill factor, \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Device** & **2D Material** & **Layered or Hybrid** & **Average Efficiency (\%)** & **Reference** \\ \hline SWCNT/Si & MoS\({}_{2}\) & Both & Hybrid 9.23 & This work \\ SWCNT/Si & Phosphorene & Hybrid & 9.4 & [37] \\ GrapheneCNT/Si & Graphene & Hybrid & 8.5 & [36] \\ Graphene/Si & Graphene & Layered & 8.0 (14.9 with an & [45] \\  & Graphene Oxide & & antireflection layer) & [45] \\ \hline GOCNT/Si &
\begin{tabular}{c} Graphene Oxide \\ (GO) \\ \end{tabular} & Hybrid & 6 & [46] \\ SWCNT/MoS\({}_{2}\)/Si & MoS\({}_{2}\) & Layered & 11.2 & [35] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Device efficiencies for various carbon nanotube/silicon (CNT/Si) devices produced using 2D materials. which are caused by the hole transport capabilities of the n-type MoS\({}_{2}\) flakes. The fact that the layered systems give the highest performance highlights that tuning of the interface between the materials in the device is the most effective way to enhance efficiency. The following are available online at [[http://www.mdpi.com/2076-3417/10/1/287/s1](http://www.mdpi.com/2076-3417/10/1/287/s1)]([http://www.mdpi.com/2076-3417/10/1/287/s1](http://www.mdpi.com/2076-3417/10/1/287/s1)). Figure S1: The absorption spectrum for the 300 \(\mu\)L SWCNTs-dispersion. Figure S2: Dark curves for the SWCNTs-n-Silicon based solar cell at different stages of treatment made using 300 \(\mu\)L of the SWCNT dispersions. Figure S3: Light curves for the SWCNTs-n-Silicon based solar cell at different stages of treatment made using 300 \(\mu\)L of the SWCNT dispersions. Table S1: The cell parameters for the reference SWCNTs-n-Si solar cell made with 300 \(\mu\)L of SWCNT dispersion. Figure S4: Light curves for the cells made with MoS\({}_{2}\)/SWCNT hybrid films of various thicknesses. Table S2: The cell parameters for devices made with MoS\({}_{2}\)/SWCNT hybrid films of various thicknesses. Figure S5: Light curves for the SWCNTs-n-Silicon reference solar cell and cells made with MoS\({}_{2}\)/SWCNT hybrids after various HF etching times. Table S3: Parameters for the reference SWCNTs-n-Si solar cell made with 300 \(\mu\)L SWCNT dispersion and cells made with MoS\({}_{2}\)/SWCNT hybrids after various HF etching times. Figure S6: Light curves for the SWCNTs-n-Silicon reference solar cell and cells made with MoS\({}_{2}\)/SWCNT hybrids using various ratios of dispersions. Table S4: The cell parameters for the reference SWCNTs-n-Si solar cell and cells made with MoS\({}_{2}\)/SWCNT hybrids using various ratios of dispersions. Figure S7: Light curves for the cells made with a layer structure with the Si first covered a MoS\({}_{2}\) layer, which is then covered by a SWCNT layer. Table S5: The parameters for cells made with a layer structure with the Si first covered a MoS\({}_{2}\) layer, which is then covered by a SWCNT layer. Figure S8: Representative light curves for the best average cells. Table S6: The parameters for the best average cells. [PERSON], [PERSON], [PERSON] and [PERSON] carried out the investigations and undertook the data analysis. [PERSON] conceptualised and supervised the project as was also responsible for funding acquisition. [PERSON] and [PERSON] were responsible for the writing--original draft preparation while all authors were involved in writing--review and editing. All authors have read and agreed to the published version of the manuscript.