Browsing by Author "Pennapa Muthitamongkol"

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    A combined effect of plasmon energy transfer and recombination barrier in a novel TiO2/MgO/Ag working electrode for dye-sensitized solar cells
    (Hindawi Limited, 2015) Chanu Photiphitak; Pattana Rakkwamsuk; Pennapa Muthitamongkol; Chanchana Thanachayanont; C. Thanachayanont; National Metal and Material Technology Center, 114, Thailand Science Park, Klong Luang, Pathumthani, Phaholyothin Road, Klong 1, 12120, Thailand; email: chanchm@mtec.or.th
    Novel TiO2/MgO/Ag composite electrodes were applied as working electrodes of dye-sensitized solar cells (DSSCs). The TiO2/MgO/Ag composite films were prepared by dip coating method for MgO thin films and photoreduction method for Ag nanoparticles. The MgO film thicknesses and the Ag nanoparticle sizes were in ranges of 0.08-0.46 nm and 4.4-38.6 nm, respectively. The TiO2/MgO/Ag composite films were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The TiO2/MgO/Ag composite electrodes were sensitized by immersing in a 0.3 mM of N719 dye solution and fabricated for conventional DSSCs. J-V characteristics of the TiO2/MgO/Ag DSSCs showed that the MgO film thickness of 0.1 nm and the Ag nanoparticle size of 4.4 nm resulted in maximum short circuit current density and efficiency of 8.6 mA/cm2 and 5.2%, respectively. Electrochemical Impedance Spectroscopy showed that such values of short circuit current density and efficiency were optimal values obtained from plasmon energy transfer by 4.4 nm Ag nanoparticles and recombination barrier by the ultrathin MgO film. � 2015 Chanu Photiphitak et al.
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    Ptsn/go co-catalyst for quasi-solid-state dye sensitized solar cells
    (Trans Tech Publications Ltd, 2018) Voranuch Somsongkul; Surassawatee Jamikorn; Chanu Photiphitak; Thapanee Sarakonsri; Viratchara Laokawee; Nutpaphat Jarulertwathana; Naruephon Mahamai; Rawinunt Thanachayanont; Suchada Srisakuna; Chris Boothroyd; Taweechai Amornsakchai; Pasit Pakawatpanurat; Pennapa Muthitamongkol; Visittapong Yordsri; Chanchana Thanachayanont; C. Thanachayanont; National Metal and Materials Technology Center, 114 Thailand Science Park, Phahonyothin Rd., Klong 1, Klong Luang, 12120, Thailand; email: chanchm@mtec.or.th
    Dye sensitized solar cells (DSSCs) consist of photoanodes (dye adsorbed porous semiconductor film), electrolytes and counter electrodes. Nanostructured materials play important parts in both the photoanodes and the counter electrodes, while dyes are there to absorb photons and generate electron-hole pairs and electrolytes are there to transfer electrons from the photoanodes to the counter electrodes. In this study, to enhance light absorption and minimize electron-hole recombination, Ag nanoparticles and MgO nanolayer were coated on TiO2, respectively. To enable a long lifetime, i.e. avoiding liquid electrolyte leakage, quasi-solid-state (QSS) DSSCs were fabricated. PtSn nanoparticles were prepared by a simple chemical reduction method on graphene oxide (GO) to compare with conventional Pt catalyst on FTO substrates as counter electrodes. An average efficiency of the QSS DSSCs with PtSn/GO co-catalysts was found to outperform that of the QSS DSSCs with conventional Pt catalyst. A mixed microstructure of the PtSn/GO co-catalyst was observed. Although, PtSn2 and Pt2 Sn3 phases were suggested by XRD, in a small region observed by EDX-STEM, it was found that C, O and Si were distributed uniformly on the graphene oxide film. Pt was also distributed uniformly, but the signal was low so there were only a few X-Ray counts across the image. There was no sign of Pt being concentrated in the particles. However, Sn was found to be concentrated in the particles without any other elements. � 2018 Trans Tech Publications, Switzerland.