ZnS/ZnO Heteronanostructure as Photoanode to Enhance the Conversion Efficiency of Dye-Sensitized Solar Cells

Abstract

ZnS/ZnO heteronanostructures were prepared to serve as the photoanode of the dye-sensitized solar cells. Two nanostructures, namely, ZnS/ZnO coaxial nanowires and ZnS/ZnO hierarchical nanowires (ZnS nanoparticles on ZnO nanowires), were successfully synthesized by chemical bath deposition and chemical etching processes, respectively. For both of the nanostructures, the ZnS coating can enhance photocurrent and conversion efficiency compared with the bare ZnO nanowires. We propose that ZnS layers in the two nanostructures take effect in different ways in that the ZnS compact layer in the coaxial structure retards the back transfer of electrons to the dye and electrolyte, while the coarse surface of ZnS nanoparticles in the hierarchical nanowires significantly enhances the adsorption of dye molecules. Hence, the ideal photoanode structure for high power-conversion efficiency should have both the compact shell layer and the high surface roughness.

Plasma‐enhanced modification of multiwalled carbon nanotube with conducting polymers for dye sensitized solar cells

“…Much research effort has been expended to enhance the efficiency and decrease the production cost of DSSCs [4][5][6][7]. In particular, optimization of cathode materials is important for achieving high-efficiency DSSCs [8,9].…”

Facile synthesis of ZnO nanocrystals via a solid state reaction for high performance plastic dye-sensitized solar cells

“…Furthermore, ZnO has a higher electronic mobility which is favorable for electron transport [17]. Another important advantage of ZnO over TiO 2 is that it can be prepared using many different techniques to obtain a great variety of morphologies [18,19]. At present, the power conversion efficiency of ZnO-based DSCs is still relatively low [17].…”

“…Therefore, extensive efforts have been made to improve the performance of ZnObased DSCs. One-dimensional (1D) nano-wires/rods/ tubes/fibers, two-dimensional (2D) nano-sheets/belts/ plates/tetrahedrons, three-dimensional (3D) hierarchical structures [16], and core-shell structures [18,20] for use in DSCs have been successfully developed by different techniques including thermal evaporation [21], dc plasma reaction [22], sputtering [23], spray pyrolysis [24], and solution-derived synthesis techniques [17]. Physical and chemical vapor-phase methods [21][22][23][24] usually involve complicated preparation processes with long reaction times and expensive equipment providing ultra-high vacuum and high temperature, leading to an increase in the production costs, making them unsuitable for large scale production.…”

Photochemical reduction of sulfur in the presence of ZnO nanoparticles in ethanol

“…In particular there are no data on the spectral and photochemical characteristics of systems containing sulfur and ZnO nanoparticles or on the characteristics of the ZnO/ZnS nanostructures that can be formed in such systems as a result of photoinduced redox transformations of the components. The ZnO/ZnS nanostructures are of great interest in connection with their potential use in technologies employing the photoluminescent [5, 6] and electroluminescent characteristics of semiconducting nanomaterials [7,8] as components of the photoanodes of solar cells [9,10] and also in photocatalysis [11].For this reason the subject of the present work was study of the spectral and photochemical characteristics of ethanol sols of ZnO containing additions of S 8 and also the characteristics of the ZnO/ZnS nanostructures formed during the photoreduction of sulfur by ethanol in the presence of the nanorods of ZnO and zinc acetate. …”

“…In particular there are no data on the spectral and photochemical characteristics of systems containing sulfur and ZnO nanoparticles or on the characteristics of the ZnO/ZnS nanostructures that can be formed in such systems as a result of photoinduced redox transformations of the components. The ZnO/ZnS nanostructures are of great interest in connection with their potential use in technologies employing the photoluminescent [5,6] and electroluminescent characteristics of semiconducting nanomaterials [7,8] as components of the photoanodes of solar cells [9,10] and also in photocatalysis [11].…”