Metal-Free Sensitizers Containing Hydantoin Acceptor as High Performance Anchoring Group for Dye-Sensitized Solar Cells

• Published in: Advanced functional materials Vol. 26; no. 31; pp. 5733 - 5740
• Main Authors: Guo, Fu-Ling, Li, Zhao-Qian, Liu, Xue-Peng, Zhou, Li, Kong, Fan-Tai, Chen, Wang-Chao, Dai, Song-Yuan
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 01.08.2016
• Subjects: Anchoring; anchoring group; Durability; dye-sensitized solar cells; high efficiencies; Hydantoin; hydantoin acceptor; Infrared; Photocurrent; Photovoltaic cells; Solar cells; Titanium dioxide
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201601305

The anchoring group in dye‐sensitized solar cells (DSSCs) profoundly affects the electron injection and durability on TiO2 films interface. Here, the hydantoin acceptor is introduced as anchoring group for DSSCs. The hydantoin based sensitizer achieves a photovoltaic efficiency of 7.66%, compared to 4.90% for sensitizer containing the conventional cyanoacrylic acid as anchoring group. Remarkably, the hydantoin anchoring group significantly enhances the electron‐injection efficiency (Φinj) and photocurrent (Jsc). The time dependent adsorption and desorption data indicate the strong binding strength and the superiority of stability for hydantoin based sensitizers. The Fourier transform infrared measurements investigate the adsorption mechanism of hydantoin on TiO2 interface. These results strongly corroborate the advantages of incorporating hydantoin as acceptor and anchoring group. As a consequence, the sensitizer HY‐4 with hydantoin approaches the photovoltaic efficiency of 8.32% under 0.1 sunlight illumination. These observations offer a new route to design and develop efficient sensitizers for DSSCs. The hydantoin acceptor is introduced into sensitizers as anchoring group and this acceptor indicates much higher electron‐injection efficiency and short‐circuit current. The hydantoin‐based sensitizers show excellent durability and better performances than the traditional carboxyl anchoring group. The results indicate the potential of hydantoin as anchoring group to substitute the traditional carboxyl group for highly efficient dye‐sensitized solar cells.