High-Efficiency Solid-State Dye-Sensitized Solar Cells Based on TiO2-Coated ZnO Nanowire Arrays

• Published in: Nano letters 2012-05, Vol.12 (5), p.2420-2424
• Main Authors: Xu, Chengkun, Wu, Jiamin, Desai, Umang V, Gao, Di
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Energy; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Natural energy; Photovoltaic conversion; Physics; Quantum wires; Solar cells. Photoelectrochemical cells; Solar energy; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl3004144

Replacing the liquid electrolytes in dye-sensitized solar cells (DSCs) with solid-state hole-transporting materials (HTMs) may solve the packaging challenge and improve the long-term stability of DSCs. The efficiencies of such solid-state DSCs (ss-DSCs), however, have been far below the efficiencies of their counterparts that use liquid electrolytes, primarily due to the challenges in filling HTMs into thick enough sensitized films based on sintered TiO2 nanoparticles. Here we report fabrication of high-efficiency ss-DSCs using multilayer TiO2-coated ZnO nanowire arrays as the photoanodes. The straight channel between the vertically aligned nanostructures combined with a newly developed multistep HTM filling process allows us to effectively fill sensitized films as thick as 50 μm with the HTMs. The resulting ss-DSCs yield an average power conversion efficiency of 5.65%.