Dye-modified ZnO nanohybrids: optical properties of the potential solar cell nanocomposites (original) (raw)
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We report the hybridization of ZnO with natural dyes [Laali, Zobo] or synthetic dye [methyl red] forming ZnO–laali, ZnO–zobo and ZnO–methyl red nanocomposites in bright colours. The structural, optical and dye photosensitization influence of the hybrid nanocomposites were studied by X-ray diffraction (XRD), scanning electron microscope (SEM), UV–Visible absorption spectroscopy and photoluminescence (PL). The surface plasmon absorption band of ZnO–laali and ZnO–zobo shifts towards red and blue, respectively, with significantly enhanced absorption intensities, indicating the interaction and optical influence of the respective dyes in photosensitization. Optical and absorption character of ZnO methyl red and bare ZnO are similar indicating the insignificant effect of methyl red on photosensitization. PL spectra of ZnO–laali and ZnO–zobo display enhanced UV light emission due not only to the surface electron transfer from their respective inherent isoplumbagin and anthocyanin to ZnO but also to the extension of the Fermi energy level to the ZnO. Dyes adopted influence the optical band gaps of the evolved hybrid nanocomposites.
International Journal of Hybrid Information Technology
This thesis examine and compares the efficiency of DSSC sensitized with natural dye extracted from Euphorbia amygdaloides and opuntia Ficus indica plant and pure ZnO, ZnO-Fe 2 O 3 and pure Fe 2 O 3 nanocomposite. The study starts by selecting natural dyes that they have good absorption spectra in the visible range using the UV-Vis spectrophotometer the selected natural dyes were Euphorbia amygdaloides and opuntia Ficus indica. Nanocomposites semiconductor oxide starting from pure ZnO, 95%ZnO-5% Fe 2 O 3 , 90% ZnO-10% Fe 2 O 3 , 80% ZnO-20% Fe 2 O 3 , and pure Fe 2 O 3 were prepared using co-precipitation method. Then the prepared semiconductor oxide particle sizes were estimated using XRD. The estimated size of the prepared nanoparticles were ZnO =39.84nm, 95%ZnO-5% Fe 2 O 3 =23.22nm, 90% ZnO-10% Fe 2 O 3 =32.44nm, 80% ZnO-20% Fe 2 O 3 =38.38nm and pure Fe2O3=35.47nm. Finally dye sensitized solar cells (DSSCs) had been assembled and characterized from each dye extracted, Euphorbia amygdaloides. (Using Ethanol) and opuntia Ficus indica (using water) and the prepared semiconductor metallic oxide. The current density-voltage characteristics in the dark and under white light illumination and also IPCE under monochromatic illuminations have been studied. Solar energy conversion efficiency (η) of the as-synthesized semiconductors sensitized by the natural dye (Euphorbia amygdaloides. and opuntia Ficus indica) was obtained in the following order ZnO>80% ZnO-20% Fe 2 O 3 >95%ZnO-5% Fe 2 O 3 >90% ZnO-10% Fe 2 O 3 > Fe 2 O 3. From the ten devices assembled best device parameter was achieved by the ethanol extract of Euphorbia amygdaloides. and pure ZnO nanoparticle semiconductor. The result was JSC=0.3696mAcm-2, VOC =0.33V, FF = 0.31 and η=0.038.
Nepal Journal of Science and Technology, 2013
Natural dye-sensitized solar cells (DSSC) are one of the most promising devices for the solar energy conversion due to their low production cost and low environmental impact. The synthesis and performance study of Zinc oxide (ZnO) nanorods based DSSC is reported in the present paper. ZnO nanorods were fabricated using sol-gel spin coating process and different types of DSSCs were fabricated using two different classes of natural dyes, xanthenes, anthocyanins and a mixed-dye with equal proportion mixture of xanthenes and anthocyanins. The ultravioletvisible (UV-Vis.) absorbance spectra were compared with performances of the cells. Efficiency of fabricated cells and cell characteristics were found to be related with absorption spectra of dyes. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 179-185 DOI: http://dx.doi.org/10.3126/njst.v13i1.7457
2018
ZnO nanoparticles (ZnO NPs) were synthesized using hydrothermal and sol-gel techniques using zinc acetate dihydrate (Zn (CH3COO)2.2H2O) as a row material and methanol as a solvent. The structural properties of ZnO NPs were studied using EDX, XRD, TEM, and the optical properties were characterized using UV-VIS and PL spectroscopies. The synthesized ZnO NPs showed high purity and revealed a wurtzite (hexagonal) crystal structure with particle size (D) ranged from 25 nm to 28 nm. The UV-VIS absorption spectra of ZnO NPs samples and sensitizing dyes were performed. The obtained ZnO NPs exhibited the direct optical bandgap 3.15 eV. Dye-sensitized solar cells (DSSCs) were fabricated using synthesized ZnO NPs as a semiconducting layer, which was dyed with different low cost dyes such as Eosin B (EB), Eosin Y (EY) and Rhodamine B (RB) that was used to sensitize the photoanode (ZnO NPs). The experimental results showed a significant efficiency for the fabricated DSSCs of synthesized ZnO NPs ...
Synthesis and characterization of Zinc Oxide nanoparticles for Dye Sensitized Solar Cells
Zinc is a transition metal of group XII. It is hexagonal in structure. Zinc oxide is classified as a semiconductor in group II-VI of the periodic table. Zinc oxide exits in two structures namely Wurzite and Cubic Zincblende. The hexagonal Wurtzite structure is most stable at ambient conditions and is most common. Zinc oxide crystalline Nanoparticles were synthesized using chemical route method. TEM was used to study the morphology and growth structure of Zinc oxide. PL and UV studies were used for understanding the optical properties of Zinc oxide Nanoparticles. The particle size ranges from 146 nm to 148 nm. The PL spectra was found to exhibit emission at 469 nm and excitation spectra was recorded at 490 nm.
Natural Dye-Sensitized Solar Cell Based on Zinc Oxide
2015
2 Abstract— Thin Film of ZnO nanoparticles paste are spread on transparent conducting ITO coated glass using doctor-blade method, the average particle size of about 16.4nm. Natural dyes extracted from pomegranate and spinach were used as sensitizers to fabricate dye sensitized solar cells (DSSCs). The thin films were studied by absorption spectra of all dyes were performed by UV-Visible spectroscopy which showed that the dye absorbed light in the visible region from (200-325)nm for chlorophyll pigment and (500-530)nm for anthocyanin pigment. The optical band gap was found to be 3.5eV. X-Ray diffraction, Atomic Force Microscopy and Scanning Electron Microscopy were also investigated.
Synthesis and Fabrication of Dye Sensitized Solar Cells based on ZnO and TiO2 Nano Composites
This article focuses on the importance of Dye Sensitized Solar Cells (DSSCs) which use the combination of ZnO and ZnO/TiO2 based semiconducting materials that capture a large range of photon energies in the solar spectrum. The nanoparticles ZnO/TiO2 were prepared by using simple chemical precipitation method. The materials were characterizations using powder X-ray diffraction (XRD), UV–Vis absorption spectra and Field emission Scanning electron microscope (FE-SEM) with Energy dispersive analysis of X-ray (EDAX). The efficiency of the material was calculated in order to know its suitability for the fabrication of DSSCs. The results confirm that the combination of ZnO with TiO2 nanomaterials show higher conversion efficiency with naturally extracted Anthroquinones dyes. This material combination is a highly promising agent for the enhancement of the conversion efficiency for the fabrication of high efficient, low cost and high stable DSSCs.
BIBECHANA, 2014
Photovoltaic solar modules, which are mostly made of silicon based solar cells, are still expensive to the common people of Nepal. The high cost is, mainly, due to the processing difficulties to get pure crystalline silicon. Here, we present results on devising efficient and low-cost dye sensitized solar cells (DSSCs). The solar cells were fabricated from transparent thin film of zinc oxide (ZnO), as a semiconductor, on top of which a thin layer of synthetic organic dye was deposited for efficient light harvesting. In order to achieve the films with optimum conditions for solar cell fabrication, we prepared transparent thin films of ZnO of various thicknesses and characterized by measuring their light transmittance by UV-Visible spectrophotometry. The results clearly show variation in transmittance curves with variation in film’s thickness. Also for finding appropriate sensitizer for ZnO nanoparticles, we extensively investigated the light absorbance of synthetic organic dyes. Among...
Key Engineering Materials, 2018
In the current study, various morphologies of zinc oxide (ZnO) including nanorods, nanoflowers, nanosheets/flakes, nanospherical particles, nanohexagonal sheets, and nanoneedles have been prepared by using single step and two-step hydrothermal processes with optimized parameters such as growth temperature, growth time and compositions of both the seed and growth solutions. Fluorine doped tin oxide (FTO) coated glass was used as the substrate. The prepared morphologies were characterized with the help of scanning electron microscopy (SEM) and the purity of nanostructures was confirmed by elemental analysis (EDX). These nanostructures were used as photo-anode material to fabricate the DSSC using a dye (Rhodamine B) for enhancing the range of solar spectrum that is to be adsorbed. Finally the fabricated solar cells were characterized in terms of their efficiency, gauged by their fill factor. Among different morphologies investigated as photo anode materials; nanosheets/flakes were foun...
Materials Science in Semiconductor Processing, 2013
We studied the influence of the synthesis route on the morphology and optical properties of zinc oxide (ZnO), with applications in dye-sensitized solar cells (DSSCs). For this purpose, we obtained surfactant capped ZnO nanopowders, in the presence of non-ionic surfactants with different structures, and demonstrated their behavior as semiconductors in DSSCs. The ZnO nanopowders and films (obtained from nanopowders using the doctor blading method) were analyzed by transmission electron microscopy (TEM), high resolution TEM (HRTEM), and selected area electron diffraction (SAED). The optical properties were examined by UV, visible spectroscopy, and the band gap energies were calculated using the Tauc equation. The values obtained for DSSCs efficiencies were in good agreement with the characteristics of ZnO, both powders and films, and can be correlated with the synthesis route. The highest efficiency (1.19%) was achieved using ZnO nanopowder capped with Triton X-100, having a mean diameter of ∼19 nm. We find that the use of capped ZnO nanoparticles is favorable for DSSCs, possibly because of the good porosity of the film and better dye adsorption. Moreover, the efficiency of the cells is influenced by the surfactant structure, due to the particle morphology.