## 3 Results and Discussion  
### Morphology Study of Cu Meshes  
The morphology and geometric characteristics of LCM and SCM are the defining parameters that have a key influence on the optoelectric properties of Cu meshes. Figure 3 shows SEM images of LCM and SCM at X200 magnification for the entire range of electroplating, before the process of embedding in a photocurable resin.  
As seen from the SEM images, electroplating leads to a width paths increase and, as a result, to the rise in the \(F\)F. SEM images show uniform copper deposition on two types of seed meshes.  
The critical question is--What is the defectiveness of the resulting mesh structures? To answer this question, one needs to understand the morphological features of the cracked template. As practice shows, the morphology of a cracked template is formed in several stages [25]. At the first stage, a primary network of cracks (Figure 3(a) green lines) is formed by relaxing mechanical stresses in the gel layer during its shrinkage. At the second and subsequent stages, in drying out the cracked template, secondary ones are formed (Figure 3(a) red lines).  
Defects arising on electroplated Cu meshes are usually associated with a violation of the integrity of the seed mesh. Based on the cracked template morphology features, it  
Figure 4: SEM image cracked template LCM (left) and SCM (right) showing primary (green lines) and secondary (red lines) cracks **(a)**; Defects on LCM 180 (**b**) and SCM 180 (**c**) (defects indicated by red circles).  
Figure 3: SEM image of Cu meshes before embedding in photocurable resin LCM 0 (**a**); LCM 30 (**b**); LCM 180 (**c**); SCM 0 (**d**); SCM 30 (**e**); SCM 180 (**f**).  
can be seen that secondary cracks have a significantly smaller width than primary cracks. As a rule, the width of secondary cracks does not exceed 1 \(\mu\)m. Narrow paths are easily damaged, resulting in defects in the form of interrupted paths being observed on the surfaces. It is worth noting that the defectiveness associated with undergrowth of lanes, attributable to secondary fractures, appears to be higher in the LCM (Figure 4b) than in the SCM (Figure 4c). This regularity can be explained by the fact that for templates with small cell sizes, the crack length turns out to be shorter, and, therefore, the probability of the appearance of a defect is reduced.  
Figure 5 shows AFM images for LCM and SCM with different copper deposition times.  
AFM data make it possible to objectively estimate the average width of copper paths and their average height for coatings with different electroplating times. Table 1 shows the averaged data for the thickness of the meshes, or the width of the paths.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Type** & **Average \(h\),** & **Average Error** & **Average** & **Average Error** & \\
**Coating** & **nm** & **\(h\), nm** & **\(b\), nm** & **\(b\), nm** & **\(FF\), \%** \\ \hline LCM 0 & 168.40 & 9.34 & 6918.72 & 1038.34 & 7.62 \\ LCM 30 & 443.14 & 19.75 & 7050.13 & 1765.39 & 7.85 \\ LCM 180 & 3722.82 & 66.35 & 11,573.96 & 1150.11 & 13.5 \\ SCM 0 & 36.20 & 6.13 & 4251.26 & 396.96 & 11.8 \\ SCM 30 & 723.03 & 50.15 & 7866.75 & 1088.62 & 19.5 \\ SCM 180 & 4792.41 & 99.68 & 12,427.67 & 1793.26 & 29.9 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Parameters of Cu meshes obtained using AFM.  
Figure 5: AFM image and profile LCM 0 (**a**); LCM 30 (**b**); LCM 180 (**c**); SCM 0 (**d**); SCM 30 (**e**); SCM 180 (**f**).  
The \(FF\) can be estimated according to the following Formula (2).  
\[FF=1-\frac{(p-b)^{2}}{p^{2}} \tag{2}\]  
where \(p\) is the average cell size and \(b\) is the average crack width. Thus, Table 1 provides a complete set of data on the change in Cu meshes' geometric and morphological characteristics in the course of electroplating.