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1. Synthesis, photovoltaic performances and TD-DFT modeling of push–pull diacetylide platinum complexes in TiO ₂ based dye-sensitized solar cells

   https://doi.org/10.1039/c4dt00301b  

   Gauthier, Sébastien; Caro, Bertrand; Robin-Le Guen, Françoise; Bhuvanesh, Nattamai; Gladysz, John A.; Wojcik, Laurianne; Le Poul, Nicolas; Planchat, Aurélien; Pellegrin, Yann; Blart, Errol; et al (January 2014, Dalton Trans.)

   In this joint experimental–theoretical work, we present the synthesis and optical and electrochemical characterization of five new bis-acetylide platinum complex dyes end capped with diphenylpyranylidene moieties, as well as their performances in dye-sensitized solar cells (DSCs). Theoretical calculations relying on Time-Dependent Density Functional Theory (TD-DFT) and a range-separated hybrid show a very good match with experimental data and allow us to quantify the charge-transfer character of each compound. The photoconversion efficiency obtained reaches 4.7% for 8e (see TOC Graphic) with the tri-thiophene segment, which is among the highest efficiencies reported for platinum complexes in DSCs. 

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2. Dye-Sensitized Solar Cells

   https://doi.org/10.18687/LACCEI2018.1.1.79  

   Orebiyi, Joshua; Barnes, B; Das, Kausik S. (August 2018, 16th LACCEI International Multi-Conference for Engineering, Education, and Technology: “Innovation in Education and Inclusion”/2414-6390)

   Dye sensitized solar cells are a type of thin film solar cell used to convert sunlight into electrical energy. These devices use a different mechanism than conventional solar cells and can be made from materials which are biocompatible and biodegradable. The simplicity of design and small environmental impact of these devices make them a likely candidate for replacing conventional PV devices. Since these solar cells are thin film cells, they can be made to be transparent and can be printed on flexible substrate, allowing their incorporation into many household objects such as windows, backpacks, walls, and other objects which would otherwise not be used for energy generation. A wide variety of fabrication techniques and device designs exist for DSSCs, each having its benefits and deficiencies; it is the purpose of this paper to evaluate some of these design variations, including different semiconductor and dye types and scaffolds, as well as semiconductor surface treatment. 

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3. Effect of Plasma Etching and Scaffolding on Dye-Sensitized Solar Cells

   Orebiyi, Joshua; Barnes, Benjamin; and Das, Kausik S. (July 2017, Global Partnerships for Development and Engineering Education: Proceedings of the 15th LACCEI International Multi-Conference for Engineering, Education and Technology)

   Dye sensitized solar cells are a type of thin film solar cell used to convert sunlight into electrical energy. These devices use a different mechanism than conventional solar cells and can be made from materials which are biocompatible and biodegradable. The simplicity of design and small environmental impact of these devices make them a likely candidate for replacing conventional PV devices. Since these solar cells are thin film cells, they can be made to be transparent and can be printed on flexible substrate, allowing their incorporation into many household objects such as windows, backpacks, walls, and other objects which would otherwise not be used for energy generation. A wide variety of fabrication techniques and device designs exist for DSSCs, each having its benefits and deficiencies; it is the purpose of this paper to evaluate some of these design variations, including different semiconductor and dye types and scaffolds, as well as semiconductor surface treatment using microwave plasma. 

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4. Open-shell donor–π–acceptor conjugated metal-free dyes for dye-sensitized solar cells

   https://doi.org/10.1039/D0ME00091D  

   Sabuj, Md Abdus; Rai, Neeraj (November 2020, Molecular Systems Design & Engineering)

   null (Ed.)

   Dye-sensitized solar cells (DSCs) have drawn a significant interest due to their low production cost, design flexibility, and the tunability of the sensitizer. However, the power conversion efficiency (PCE) of the metal-free organic dyes is limited due to the inability of the dye to absorb light in the near-infrared (NIR) region, leaving a large amount of energy unused. Herein, we have designed new DSC dyes with open-shell character, which significantly red-shifts the absorption spectra from their counterpart closed-shell structure. A small diradical character ( y < 0.10) is found to be beneficial in red-shifting the absorption maxima into the NIR region and broadening up to 2500 nm. Also, the open-shell dyes significantly reduce the singlet–triplet energy gaps (Δ E ST ), increase the total amount of charge-transfer to the semiconductor surface, reduce the exciton binding energy, and significantly increase the excited-state lifetimes compared to the closed-shell systems. However, the closed-shell dyes have higher injection efficiency with increased intramolecular charge transfer (ICT) character. Our study reveals the design rule for open-shell DSC dyes to be able to absorb photons in the NIR region, which can increase the efficiency of the solar cell device. 

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5. Iodine binding with thiophene and furan based dyes for DSCs

   https://doi.org/10.1039/c8cp03065k  

   Baumann, Alexandra; Cheema, Hammad; Sabuj, Md Abdus; McNamara, Louis E.; Zhang, Yanbing; Peddapuram, Adithya; Nguyen, Suong T.; Watkins, Davita L.; Hammer, Nathan I.; Rai, Neeraj; et al (January 2018, Physical Chemistry Chemical Physics)

   Iodine binding to thiophene rings in dyes for dye-sensitized solar cells (DSCs) has been hypothesized to be performance degrading in a number of literature cases. Binding of iodine to dyes near the semiconductor surface can promote undesirable electron transfers and lower the overall efficiency of devices. Six thiophene or furan containing dye analogs were synthesized to analyze iodine binding to the dyes via Raman spectroscopy, UV-Vis studies, device performance metrics and density functional theory (DFT) based computations. Evidence suggests I 2 binds thiophene-based dyes stronger than furan-based dyes. This leads to higher DSC device currents and voltages from furan analogues, and longer electron lifetimes in DSC devices using furan based dyes. Raman spectrum of the TiO 2 surface-bound dyes reveals additional and more instense peaks for thiophene dyes in the presence of I 2 relative to no I 2 . Additionally, broader and shifted UV-Vis peaks are observed for thiophene dyes in the presence of I 2 on TiO 2 films suggesting significant interaction between the dye molecules and I 2 . These observations are also supported by DFT and TD-DFT calculations which indicate the absence of a key geometric energy minimum in the dye–I 2 ground state for furan dyes which are readily observed for the thiophene based analogues. 

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