Linkage modification of a zinc oxide photoelectrode prepared with polyethylene glycol for electron transport improvement in dye-sensitized solar cells

Abstract

The purpose of this study is to synthesize ZnO aggregate films using simple precipitation with polymer modification for linkage improvement of the ZnO photoelectrode. The starting materials of zinc acetate solution and ammonia solution were mixed under violent stirring conditions. A portion of the polymer (polyethylene glycol) was slowly added into the mixed solution to obtain the viscous ZnO precursor. The precursor was then coated onto a fluorine-doped tin oxide substrate and annealed to form ZnO films. The scanning electron microscopy results revealed the formation of ZnO aggregates with flower-like microstructures. The appearance of Zn and O elements indicated a fair ZnO formation. The X-ray diffraction patterns and Raman shift confirmed the hexagonal wurtzite crystal structure of the ZnO aggregates. For dye-sensitized solar cell (DSSC) application, power conversion efficiency was enhanced because of the improved photovoltaic characteristics including the open-circuit voltage, fill factor, series resistance, shunt resistances and recombination resistance, perhaps, due to the large particle size of the ZnO aggregates and their flower-like microstructures. The flower-like microstructure likely acts as a bridge to link each ZnO particle. The flower-like microstructure plays the role of an express pathway in electron transport in the DSSC. Therefore, the ZnO aggregation with a flower-like microstructure has the potential to improve the electron transport for efficiency enhancement of a DSSC.

Incorporation of Fe and Cu for antibacterial performance enhancement of Fe-Cu-ZnO nanocomposites synthesized by a facile chemical precipitation

“…For analyzing antibacterial performance, bacterial activities of X. campestris, P. aeruginosa, and P. fluorescens were monitored from the optical density at 600 nm [29]. Then, the antibacterial performance was evaluated in term of inhibition rate, calculated from the Equation (6) [7];…”

“…ZnO-based antibacterial performance has been demonstrated in varieties of bacteria that cause disease in plants, animals, and humans. For examples, the inhibition rates of Bacillus thuringiensis israelensis (Bti) and Escherichia coli (E. coli) were investigated using ZnO tetrapods [7]. It was found that the inhibition rates increased as a function of ZnO tetrapod concentration, and both strains were completely inhibited at the concentration of 0.75 mg•ml -1 [7].…”

“…For examples, the inhibition rates of Bacillus thuringiensis israelensis (Bti) and Escherichia coli (E. coli) were investigated using ZnO tetrapods [7]. It was found that the inhibition rates increased as a function of ZnO tetrapod concentration, and both strains were completely inhibited at the concentration of 0.75 mg•ml -1 [7]. The bactericidal efficiency of rare earth element (REE) doped ZnO nanoparticles was also investigated against Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus), Proteus mirabilis (P. mirabilis), and Salmonella typhi (S. typhi) [8,9].…”

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“…The XRD results exhibit similar diffraction patterns for all samples, which corresponds to the hexagonal wurtzite structure of ZnO, in agreement with the standard JCPDS card no. 36-1451[11]. To investigate the influence of yttrium content on the crystallization of Y-doped ZnO, the crystal characteristics including crystalline size (D), lattice constant (a and c), and d-spacing (d) were calculated according to Eqs.…”