## 3 Results and Discussion
### Optical and Electrical Properties  
PSi layers are proposed for optoelectronic applications, so it is straightforward to examine the effect of the modification on the setup on the parameters of a semiconductor junctions. The simple form of these junctions is the ideal diode, for which the current and voltage are related using the following equation [37]:  
\[I_{D}=I_{0}\bigg{[}exp^{\frac{qV}{nk_{B}T}}-1\bigg{]} \tag{1}\]  
where I\({}_{D}\) is the dark current, I\({}_{0}\) is the reverse saturation current, n is the diode ideality factor, k\({}_{B}\) is Boltzmann constant, and T is the absolute junction temperature. The ideal diode equation assumes that all recombination processes occur via band to band transitions or through traps in the bulk of the device. However, recombination could occur in other areas of the device, leading to losses in the overall performance of the diode. As such, a modified equation used for non-ideal diodes is given by the expression [37]:  
\[I_{D}=I_{0}\bigg{[}exp^{\frac{qV}{nk_{B}T}}-1\bigg{]}+\frac{V-IR_{g}}{R_{sh}} \tag{2}\]  
Large values of Rs cause power to be dissipated in solar cells, while low Rsh leads to power losses by providing an alternate current path for the light-generated current. The current - voltage lines for junction of both samples produced by Pt and Si electrodes on S1 substrate are shown in Figure 7a, where the inset is a schematic of the fabricated schottky junctions. The fitting of these two lines to the non ideal diode equations reveals a slight differences in the diode characteristics in each case. The measured electrical parameters confirm that the fabricated junctions are suitable as Schottky diodes for use in optoelectronic devices. Figure 6: SEM images for the silicon cathode before (**a**), and after (**b**) the anodization process. Figure 7: (**a**) Current\(-\)voltage curves for sample fabricated on S1 substrate using Pt cathode (black) and Si cathode (red), and the inset for the junction structure. (**b**) Spectral reflectance for PSI layer on substrate S1 using Pt cathode (black) and Si cathode (red). A slight variation in the electrical parameters was observed between the samples prepared with Pt and Si counter electrodes. However, the ideality factor (n) is lower in the case of the device based on the Si electrode during the etching process of the PSi layer. This finding confirms the improvement in the homogeneity and uniformity of the fabricated PSi layers when using an asymmetric electrode, as confirmed by SEM analysis. All parameters are summarized in Table 2. The optical and electrical properties of PSi layers change at different levels of porosity [38; 39; 40]. A detailed analysis of these characteristics established the correlation between morphology, porosity, and electrical properties of PSi layers anodized using a Pt electrode. As a conclusion a PSi layer consists of air, amorphous silicon, silicon nanocrystals, and silicon dioxide [41; 42]. These components are greatly influenced by the structure and porosity of the fabricated layer. The SEM images (see Figures 2-4) revealed that the pore size increases in the case of PSi layers fabricated using a symmetric Si electrode. This indicates that the porosity of PSi layers increases when a symmetric electrode is used when compared with samples fabricated using Pt electrode under the same anodization conditions. Consequently, the resulting current is reduced at the same applied voltage for sample S1 prepared using a symmetric Si cathode, as shown in Figure 7a. The decrease in the electrical conductivity at higher porosity is linked to the widening of the band gap of the PSi layer at higher porosity [43]. The porosity and size distribution of PSi layers have a significant impact on spectral reflectance of the samples [44], making it a popular choice for antireflective coatings in optoelectronic devices [2; 45]. Reducing optical losses through reflection has a direct impact in improving the overall device performance with maintaing a good electrical conduction.