## 1 Introduction  
Dye-sensitized solar cells (DSCs) remain a promising and intensely studied area of research after two decades of exploration [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15]. In typical n-type DSC devices, dye molecules are first photoexcited followed by the transfer of electrons to the conduction band (CB) of TiO\({}_{2}\). The electrons then traverse an external circuit before travelling back to the oxidized dye via a redox shuttle after collection at a counter electrode. The dye is one of the most important components of DSC devices for determining which photon energies are useable. Broad UV-Vis-near-infrared (NIR) absorption properties are crucial for realizing the highest efficiency DSC devices possible [16]. A DSC device employing organic dyes surpassing 14% power conversion efficiency (PCE) has been reported owing to well-positioned energy levels, high extinction coefficients, and strong binding properties [17]. However, in order to further improve DSC device performances, dyes with NIR absorption (>750 nm) are required. In this work,structure-property relationships of quinoxaline-based dual donor and dual acceptor (DD-\(\pi\)-AA) dyes are explored with absorptions extending to 800 nm. Donor-\(\pi\) bridge-acceptor (D-\(\pi\)-A) and D-A\({}^{\prime}\)-\(\pi\)-A (where A\({}^{\prime}\) is an auxiliary acceptor) dye constructs have become increasingly popular in DSC research [4; 5; 9; 18; 19]. Fueled by PCEs in excess of 13%, this direction remains heavily pursued [17; 20; 21]. Additionally, tightly bound anchors are crucial in achieving higher efficiencies, because they allow co-sensitization and co-deposition of insulators to facilitate panchromatic absorption and to protect against the transfer of electrons from the TiO\({}_{2}\) CB to the oxidized redox shuttle (recombination), respectively. As a key example, **ADEKA-1**-based devices have used these strategies to set the current record for DSC device efficiency at 14.3% [17]. The silanol anchoring group is regarded as both one of the strongest anchoring groups, with efficient electron transfers to TiO\({}_{2}\), and as a very challenging functional group to synthesize and employ in devices [22]. In this regard, sensitizers with panchromatic absorption and strong binding through multiple carboxylic acid anchors, such as with the DD-\(\pi\)-AA design, are highly attractive [23]. Quinoxaline-based dyes employing the DD-\(\pi\)-AA molecular framework have demonstrated broad absorptions and TiO\({}_{2}\) dissociation rates up to 180 times slower than dyes employing a traditional D-\(\pi\)-A structure [24]. Thienopyrazine (TPz)-based DD-\(\pi\)-AA dye, **AP3**, has shown a PCE of 5.5% (>10% under low light when co-sensitized) with panchromatic absorption [25; 26]. Energetically, the PCE of devices made with **AP3** could be increased by destabilizing the low-energy excited-state to facilitate faster electron injection into the TiO\({}_{2}\) CB by forgoing the need for excessive lithium iodide (LiI), which is known to lower DSC device photovoltages [25]. We reasoned that the use of a benzene in place of the thiophene group of TPz could broaden the dye optical energy gap enough to raise the dye excited-state energy without fully sacrificing panchromatic absorption properties [27; 28; 29]. Dyes **AP6**, **AP8**, **AP9**, and **AP12** were selected as target dyes, which vary at the donor and acceptor regions. **AP6** and **AP8** have been previously reported to have strong binding to TiO\({}_{2}\) and only differ at the dual carboxylic acid anchors, with **AP6** having a phenyl space between the anchors and the quinoxaline group (Figure 1) [24]. Both **AP6** and **AP8** had yet to be evaluated in DSC devices prior to this study, and both dyes require photons higher in energy than are present in the NIR region. Dye designs strategies for overcoming this limited absorption focus on extending conjugation, planarization of the \(\pi\)-conjugated system, and the increasing of the electron-donating/accepting group strengths.