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    Dithizone, carminic acid and pyrocatechol violet dyes sensitized metal (Ho, Ba& Cd) doped TiO2/CdS nanocomposite as a photoanode in hybrid heterojunction solar cell
    (Elsevier Sci Ltd, 2022) Ullah, Naimat; Shah, Syed Mujtaba; Erten-Ela, Sule; Ansir, Rotaba; Hussain, Hazrat; Qamar, Samina; Usman, Muhammad
    Considering the great importance of nanocomposite based photo-active nanomaterials for a variety of elec-tronics, photonics and photovoltaics application, it is always worth considering to synthesize new hetreos-tructure. This paper describes the sol-gel and hydrothermal synthesis of metal (holmium, barium, and cadmium) doped TiO2/CdS nanocomposites for photoanode applications. Various characterization techniques, including XRD, FTIR, UV-VIS, EDX, and SEM were used to examine the synthesized heterostructures. The band gap of pure TiO2 NPs is 3.10 eV, which was effectively decreased to 2.16 eV by doping and coupling with CdS. The nano-material's crystallinity, crystallite size, morphology and elemental composition were determined by XRD, SEM and EDX, respectively. As sensitizers, the organic dyes dithizone, carminic acid, and pyrocatechol violet were used. FTIR was used to analyze the effective dye grafting on the surface of nanomaterials. In the presence of hole conducting P3HT polymer as solid state electrolyte, the sensitized materials were evaluated for solid state dye -sensitized solar cells. Compared to the reference device, Cd-TiO2/CdS photosensitized using Pyrocatechol violet dye demonstrated the highest efficiency of 2.68% (0.82%). Other parameters of this device, including open circuit voltage (Voc) and short circuit current (Jsc), were determined to be 16.97 mA cm2 and 0.41V, respectively.
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    Pyrocatechol violet sensitized cadmium and barium doped TiO2/ZnO nanostructures: As photoanode in DSSC
    (Elsevier Sci Ltd, 2021) Ullah, Naimat; Shah, Syed Mujtaba; Ansir, Rotaba; Erten-Ela, Sule; Mushtaq, Syed; Zafar, Saima
    Cadmium and barium doped TiO2 nanoparticles and their respective heterostructured nanomaterials (TiO2/ZnO) were successfully synthesized through simple sol-gel and reflux methods respectively. Optical, structural and morphological analysis of as synthesized material were done by using UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-Ray analysis (EDX). The band gap values were calculated from the optical absorption spectra of nanomaterials. The band gap of TiO2 NPs (3.10 eV) was effectively tuned up to 2.82 eV by doping it with different concentrations of cadmium and barium followed by coupling with ZnO nanoparticles. The crystalline nature and phase purity of the materials were confirmed through XRD. Morphological analysis and elemental composition studies were performed with the help of SEM and EDX. Functional groups were detected through FTIR analysis. The nanostructured materials were used in combination with P3HT (as a hole conducting polymer) to fabricate photoactive blend for dye sensitized solar cell. The photovoltaic performances of fabricated device were investigated by using current voltage (I-V) measurements. The results showed that metal doped TiO2 and their respective nano structures (TiO2/ZnO) showed better conversion efficiencies than undoped TiO2. The maximum conversion efficiency (eta) was observed for Pyrocatechol violet sensitized Cd-TiO2/ZnO heterostructured nanomaterial which is 1.84%. The corresponding current density was found to be 13.11 mA/cm(2).
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    Selected organic dyes (carminic acid, pyrocatechol violet and dithizone) sensitized metal (silver, neodymium) doped TiO2/ZnO nanostructured materials: A photoanode for hybrid bulk heterojunction solar cells
    (Pergamon-Elsevier Science Ltd, 2022) Ullah, Naimat; Erten-Ela, Sule; Shah, Syed Mujtaba; Hussain, Hazrat; Ansir, Rotaba; Qamar, Samina
    A photoactive nanohybrid material consisting of pyrocatechol violet, carminic acid and dithizone dyes functionalized silver and neodymium-doped TiO2/ZnO nanostructured materials is reported here, as photoactive blend, for solid-state dye sensitized solar cell. First of all we synthesized metals (silver, neodymium) doped (TiO2) Titanium oxide nanoparticles and their nanocomposites (TiO2/ZnO, M-TiO2/ZnO) using the sol-gel and reflux technique, respectively. The synthesized samples were then characterized by UV-Visible spectroscopy, X-Ray diffraction Analysis (XRD), Scanning electron microscopy (SEM), Energy dispersive X-Ray Analysis (EDX), and Fourier Transform infrared spectroscopy (FTIR). Optical studies were done through UV-Visible spectroscopy and the absorption spectra were used to calculate band gaps. The value of the energy gap for TiO2 nanoparticles is 3.10 eV which was gradually tuned to 2.47 eV after incorporating metals (Ag and Nd) and forming respective nanocomposites. X-Ray diffraction Analysis (XRD) patterns revealed the purity and crystallinity in samples. Scanning electron microscopy (SEM) confirmed the irregular morphology (nanorods and spherical shaped) of ZnO and TiO2 nanostructures respectively. The elemental composition of nanomaterials was successfully investigated using energy dispersive X-ray analysis (EDX). In the absence of any impurities, Fourier Transform infrared spectroscopy (FTIR) was used to identify the functional groups in synthesized material. For device fabrication, a solid-state electrolyte, P3HT, a hole conducting polymer was used. Characterization of fabricated solar cells was done using I-V measurements. Under simulated solar irradiation, the DSSC based on pyrocate-chol violet sensitized neodymium doped TiO2/ZnO nanohybrid materials exhibited the best PCE (power conversion efficiency) of 2.38 % and significantly improved Jsc (short circuit current density) of 15.68 mA/ cm2 as compared to carminic acid and dithizone in photovoltaic measurements. The improved power conversion efficiency of this device is ascribed to the particle size, increased dye adsorption, increased surface area and thus improved short circuit current density (Jsc). (c) 2022 Published by Elsevier B.V.