Single-crystalline porous ZnO nanosheet frameworks for efficient fully flexible dye-sensitized solar cells

• Published in: Journal of alloys and compounds 2017-02, Vol.695, p.3324-3330
• Main Authors: Luo, Qiu-Ping, Wang, Bo, Cao, Yuanzhi
• Format: Article
• Language: English
• Subjects: Flexible dye-sensitized solar cells; Poly(3,4-ethylenedioxythiophene) counter electrode; Porous nanosheet frameworks; Single crystalline; Zinc oxide
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.10.130

The growth of single-crystalline porous ZnO nanosheet frameworks (ZnO NSFs) was performed with a simple hydrothermal approach. The highly transparent poly(3,4-ethylenedioxythiophene) (PEDOT) film was prepared by an in-situ electrodeposition method on flexible ITO-PET substrate. Moreover, ZnO NSFs and PEDOT were made as photoanodes and counter electrodes (CE) for assembling fully flexible dye-sensitized solar cells (DSSCs), respectively. The interconnected nanostructures of ZnO NSF can deliver direct electron transport paths resulting in reduced recombination rate and accelerated electron transport. The PEDOT/ITO-PET exhibits outstanding catalytic ability in the reaction of I‾/I3‾ redox couple. A power conversion efficiency of 2.97% obtained from the fully flexible DSSCs, showed a comparable photovoltaic performance to the device with Pt CE. The highly photovoltaic performance can be mainly ascribed to the unique structure of porous ZnO NSFs and the outstanding catalytic properties of PEDOT CE. Novel porous ZnO nanosheet frameworks (ZnO NSFs) on Ti-foil substrates consisting of innumerable single crystalline interconnected short nanorods and highly transparent poly(3,4-ethylenedioxythiophene) film on flexible ITO-PET substrates were employed for assembling fully flexible devices. The electrochemical impedance spectroscopy, IMPS and IMVS indicated that the ZnO NSFs/Ti based DSSCs exhibit lower recombination rate and longer electron lifetime than those based on commercial ZnO nanoparticles/Ti. The power conversion efficiency of the fully flexible DSSCs was 2.97%, showing a comparable photovoltaic performance to the rigid cell with Pt counter electrode. [Display omitted] •Porous ZnO nanosheet frameworks were prepared by simple procedure.•Reduced recombination rate have been demonstrated.•A flexible DSSCs device based on PEDOT/ITO-PET counter electrode was assembled.•The ZnO photoanode based flexible DSSCs achieved a high efficiency of 2.97%.