## 3 Result and Discussion
### Photovoltaic Analysis  
Based on optical, electrochemical, and computational data, all of the dyes studied can perform well in I\({}^{-}\)/I\({}_{3}\)\({}^{-}\)/TiO\({}_{2}\)-based DSCs. The devices were analyzed under AM 1.5 G incident solar simulation with PCEs calculated according to the equation, PCE = \((J_{\text{SC}}\times V_{\text{OC}}\times FF)/I_{0}\), where \(J_{\text{SC}}\) is the short-circuit current density, \(V_{\text{OC}}\) is the open-circuit voltage, \(FF\) is the fill factor, and \(I_{0}\) is the incident light intensity equal to 1 sun in this study. The highest PCE of the series was measured for **AP6** at 3.7% with a \(J_{\text{SC}}\) value of 7.0 mA/cm\({}^{2}\) (Figure 5 and Table 2). **AP6** also had the highest observed \(V\)oc value of 694 mV, with the remaining dyes having very similar \(V_{\text{OC}}\) values of 591-615 mV, which also contributed to **AP6** showing the highest PCE of the series. **AP6**-based devices have the highest \(J_{\text{SC}}\) value for the series followed by **AP12**\(>\)**AP9**\(>\)**AP8**. Interestingly, the \(J_{\text{SC}}\) trend followed the same trend for absorption onsets on TiO\({}_{2}\), with the longest wavelength absorbing dyes producing the highest \(J_{\text{SC}}\) values except for **AP6**. **AP6** had the narrowest absorption of the series yet had the highest photocurrent in DSC devices. This was likely the result of a significantly higher molar absorptivity for **AP6** relative to the other dyes in the series. Figure 4: Frontier molecular orbital distributions of **AP6**, **AP8**, **AP9**, and **AP12**. **AP6** also showed the highest peak incident photon-to-current conversion efficiency (IPCE) value of the dyes in this series at \(>\)70%. **AP8**, **AP9**, and **AP12** reached a peak IPCE of \(\sim\)40%, which was roughly half that of **AP6**. This observation correlates to the observed molar absorptivities for **AP8**, **AP9**, and **AP12** being roughly half of **AP6**. The \(J_{\text{SC}}\) values for **AP8**, **AP9**, and **AP12** ranged from 3.8 to 6.1 mA/cm\({}^{2}\), which was significantly closer to the \(J_{\text{SC}}\) value of **AP6** due to the broader absorption of these dyes. It is noteworthy that the broadest IPCE spectrum was observed for **AP12**, which reached 800 nm. Very few organic dyes produce electricity from such a low-energy wavelength [35]. Importantly, through this double donor, double anchor design strategy, the IPCE breadth can be increased relative to a more traditional D-A-\(\pi\)-A dye design using the same TPA donor, quinoxaline auxiliary acceptor, thiophene \(\pi\)-bridge, and the stronger-accepting cyanoacrylic acid, and, for the case of **AP12**, the IPCE breadth exceeds that observed for even metal-based dyes such as **N719**[36]. Given this improvement on DSC device electricity production wavelength range and the observed slow desorption from TiO\({}_{2}\) surfaces for DD-\(\pi\)-AA structures (similar to dual anchors popularized with heteroleptic-Ru dyes), this organic design is attractive [37; 38]. Molecular engineering strategies to improve the molar absorptivity are important to improve the peak IPCE value, and the focus of future designs should be on maintaining or extending this exceptional IPCE breadth. Interestingly, both **AP8** and **AP12** showed a dramatic red-shift in the IPCE onset relative to the film absorption on TiO\({}_{2}\) of \(\geq\)80 nm (Table 1). This change was likely due in part to the interaction of the dyes with the electrolyte, whereas if this were the result of a solid-state ordering on film (such as \(J\)-aggregates) this shift would have presented during the TiO\({}_{2}\) film absorption studies [39]. Accounting for these interactions energetically when rationally designing DSC dyes is not straightforward, but these interactions can have profound effects on dye energetics.