## 3 Results and Discussions
### Photovoltaic Properties
#### 3.3.3 Electron Regeneration Energy (\(\Delta G^{region}\))  
The energy required in a DSSC to convey an electron from a reduced dye molecule to an oxidized electrolyte molecule is crucial for renewing the dye and completing the electron transport cycle. In a DSSC, a dye molecule is converted into a cation (positively charged ion), leading to the injection of the dye molecule's photoexcited electrons into the semiconductor's conduction band. The resulting electron-deficient dye can be recovered by accepting an electron from a reduced electrolyte molecule, typically a redox pair dissolved in the electrolyte solution. Electron regeneration involves the moment of electrons at the DSSC's counter electrode [42].  
The efficiency of electron regeneration depends on a number of factors, including the electrical properties of the dye and electrolyte molecules, the redox potentials of the redox pair, and the kinetics of the electron transfer procedure. When evaluating the DSSC's performance, electron regeneration energy is a critical component to consider as it impacts the overall efficacy of the system. Electron regeneration energy (\(\Delta G^{region}\)) may be calculated using the energy difference between the reduced state of the dye and the oxidized state of the redox pair. This energy can also be measured experimentally using techniques such as cyclic voltammetry. The calculation of \(\Delta G^{region}\) is performed using Equation (4) [43].  
\[\Delta G^{region}_{dye}=E^{electrolyte}_{redox}+E^{dye}_{ox} \tag{4}\]  
where:  
\(\Delta G^{region}_{dye}=\) Electron regeneration energy  
\(E^{electrolyte}_{redox}=\) the redox potential  
\(E^{dye}_{ox}=\) Dye's ground state oxidation potential energy.  
As shown in Table 3, the findings indicate that pelargonidin dye derivatives exhibited the highest values of electron regeneration efficiency among the investigated dyes, in both the gas and ethanol solvent phases. In the gas phase, the decreasing order of the electron regeneration efficiency is pelargonidin > petunidin > delphinidin > cyanidin > peonidin, but in the solvent phase, the order is pelargonidin > petunidin > delphinidin > cyanidin > peonidin. Effective electron regeneration is crucial for the device to function at its peak and keep a steady current flow.  
Among the examined dyes, pelargonidin demonstrated the highest electron regeneration efficiency. This suggests that pelargonidin has a larger capacity to regenerate electrons effectively, allowing a faster rate of electron transfer back from the semiconductor to the dye molecule. Further supporting evidence that pelargonidin supports effective dye regeneration comes from the high \(\Delta G^{region}\) (energy difference for electron regeneration) reported in this compound. The increased \(\Delta G^{region}\) in pelargonidin suggests a more favorable energy environment for the regeneration process, which may lead to an enhanced electron transfer back to the dye and, as a result, an improvement in the short-circuit current (\(J_{SC}\)) of the DSSC.  
Overall, pelargonidin exhibited superior greater electron regeneration efficiency compared to other dyes, suggesting its potential as a promising sensitizer for DSSCs. By enhancing current flow and boosting overall power conversion efficiency, the effective electron regeneration made possible by pelargonidin can help a device function better.