Assembly and characterization of ZnO nanoparticles for Grätzel's solar cells  

Abstract

This research aimed to build hybrid solar cells, based on Grätzel method. We used the Polyethylene Terephthalate (PET) polymer as a substrate containing a layer of Indium Tin Oxide (ITO). Films of ZnO nanoparticles (ZnO NPs) synthesized by Pechini Method, and four different dyes were tested: Congo Red (CR), Bromocresol Green (BG), Acridine Orange (AO) and a Ruthenium Complex (RC). ZnO NPs were analyzed by XRD, which generated peaks corresponding to hexagonal wurtzite crystalline structure. We also conducted analysis by UV-Vis. Spectroscopy and Transmission Electron Microscope (TEM). Rietveld analysis determined the crystal size of 115.23 ± 28.16 nm. The deposition of ZnO and dye thin films were made through spin-coating. The electrical properties of the formed films were characterized with Van der Pawn method. Efficiency in converting light in electricity under an OSRAM 20W light bulb was tested after the devices were built. The smaller sheet resistance results were obtained for material containing: PET/ITO/ZnO/CR and PET/ITO/ZnO/AO. As expected, the best open-circuit voltage (Voc) results reached were 64 and 73 mV to CR and AO, respectively. Therefore, the results demonstrated satisfactory interaction between the ZnO-Dye-Electrolyte layers.

High Performance Zinc Oxide Nanorod-Doped Ion Imprinted Polypyrrole for the Selective Electrosensing of Mercury II Ions

“…Zinc oxide is considered to be a very important functional oxide among many semiconductor metal oxides [37] and, more generally, is one of the most used materials in applied sciences currently. It is a semiconductor; its wurtzite structure has a wide band gap (Eg = 3.37 eV at 300 K) and a large exciton binding energy (60 meV) [38,39]; it has excellent biocompatibility, good chemical/thermal stability, mixed chemical bonds (covalent/ionic) [37], and it excellent properties allow it to be used in many applications as a nanomaterial, including in Gratzël cells [40], varistors [41], optical waveguides [42] and in many optoelectronic devices [38,43]. In addition to these applications, ZnO is widely used in the field of sensors, i.e., gas and heavy metal ion sensors [37,[44][45][46][47][48][49][50].…”