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Research Article

High performance novel flexible perovskite solar cell based on a low-cost-processed ZnO:Co electron transport layer

Feriel Bouhjar1,2,4( )Lotfi Derbali3,4Bernabé Marí1
Institut de Disseny i Fabricació (IDF) - Departament de Física Aplicada, Universitat Politècnica de València, Camí de Vera s/n, 46022 Valencia, Spain
Photovoltaic Laboratory, Research and Technology Centre of Energy (CRTEn), Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif, Tunisia
Laboratory of Semiconductors, Nanostructures and Advanced Technology, Research and Technology Center of Energy (CRTEn), Borj-Cedria Science and Technology Park, BP 95,2050 Hammam-Lif, Tunisia
Department of Physics, College of Sciences and Humanities, Al Quwayiyah, Shaqraa University, Al Quwayiyah, Saudi Arabia
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Abstract

In this work, high quality uniform and dense nanostructured cobalt-doped zinc oxide (ZnO:Co) films were used as electron-transport layers in CH3NH3PbI3-based planar heterojunction perovskite solar cells (PSCs) on a flexible conductive substrate. Highly photo catalytically active ZnO:Co films were prepared by a low cost hydrothermal process using the aqueous solution of zinc nitrate hexahydrate, hexamethylenete-tramine and cobalt (II) nitrate hexahydrate. ZnO:Co films were deposited on indium tin oxide (ITO) covered polyethylene terephthalate (PET) flexible substrates. The growth was controlled by maintaining the autoclave temperature at 150 °C for 4 h. The CH3NH3PbI3 layer was deposited on the ZnO:Co films by spin coating. Spiro-OMeTAD was employed as a hole-transporting material. The structural, morphology and optical properties of the grown ZnO nanostructures were characterized by X-ray diffraction (XRD), field-emission scanning electron microcopy (FESEM), energy-dispersive X-ray spectrometry (EDX), ultraviolet-visible (UV-Vis) and photoelectrochemical propriety. XRD spectra showed that both ZnO and ZnO:Co nanorods had a hexagonal wurtzite structure with a strong preferred orientation along the (002) plane. The surface morphology of films was studied by FESEM and showed that both the pure and Co-doped ZnO films had hexagonal shaped nanorods. In the steady state, the ZnO electrode gave a photocurrent density of about 1.5 mA/cm2. However, the Co-doped ZnO electrode showed a photocurrent density of about 6 mA/cm2, which is 4-fold higher than that of the ZnO electrode. Based on the above synthesized Co-doped ZnO films, the photovoltaic performance of PSCs was studied. The Co-doped ZnO layers had a significant impact on the photovoltaic conversion efficiency (PCE) of the PSCs. The latter was attributed to an efficient charge separation and transport due to the better coverage of perovskite on the nanostructured Co-doped ZnO films. As a result, the measured PCE under standard solar conditions (A M 1.5G, 100 mW/cm2) reached 7%. SCAPS-1D simulation was also performed to analyze the effect of the co-doped ZnO thin film on the corresponding solar cell performances.

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Nano Research
Pages 2546-2555
Cite this article:
Bouhjar F, Derbali L, Marí B. High performance novel flexible perovskite solar cell based on a low-cost-processed ZnO:Co electron transport layer. Nano Research, 2020, 13(9): 2546-2555. https://doi.org/10.1007/s12274-020-2896-4
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Received: 11 March 2020
Revised: 19 May 2020
Accepted: 21 May 2020
Published: 26 June 2020
© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2020
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