Morphology control of low temperature fabricated ZnO nanostructures for transparent active layers in all solid-state dye-sensitized solar cells

Based on a method using sol-gel chemistry combined with diblock copolymer templating, a low-temperature route to fabricate zinc oxide (ZnO) films with tunable morphologies including foam-like, worm-like and sphere-like structures is demonstrated. The morphologies are probed using scanning electron microscopy and grazing-incidence small-angle X-ray scattering. Based on controlled nanostructured ZnO films, all solid-state dye-sensitized solar cells (ssDSSCs) are prepared, for which every layer is deposited at low temperature to reduce the energy consumption of the manufacturing process. Transparent active layers for ssDSSCs are obtained, which demonstrates the possibility for building integrated solar cells. The ssDSSCs with a worm-like ZnO morphology, exhibiting relatively better ordered interconnected three-dimensional structures and larger meso-pore sizes, show the highest power conversion efficiencies and almost 100% efficiency of charge separation and collection for the absorbed photons. After 120 days, almost 80% of the initial power conversion efficiency is maintained in ambient air conditions, which demonstrates good long-term stability of the ssDSSCs even without special encapsulation.
Export Date: 9 May 2018; Article; CODEN: JMCAE; Correspondence Address: Müller-Buschbaum, P.; Technische Universität München, Physik-Department, Lehrstuhl für Funktionelle Materialien James, Franck-Str. 1, Germany; email: muellerb@ph.tum.de; Funding details: CSC, China Scholarship Council; Funding details: DESY, Deutsches Elektronen-Synchrotron; Funding details: Helmholtz Association; Funding details: UGS, University Graduate School, Florida International University; Funding details: HGF, Human Growth Foundation; Funding text: Financial support by TUM.solar in the context of the Bavarian Collaborative Research Project Solar Technologies Go Hybrid (SolTech), by the Nanosystems Initiative Munich (NIM) and by the International Research Training Group 2022. Alberta/ Technical University of Munich International Graduate School for Environmentally Responsible Functional Hybrid Materials (ATUMS) is gratefully acknowledged. K. W. and D. Y. acknowledge the China Scholarship Council (CSC). The authors thank Yu Tong from Ludwig-Maximilians-Universität München for helping with the SEM and PL measurements. Portions of this research were carried out at the synchrotron light source PETRA III at DESY. DESY is a member of the Helmholtz Association (HGF). QC 20180530