Olive-shaped ZnO nanocrystallite aggregates as bifunctional light scattering materials in double-layer photoanodes for dye-sensitized solar cells. (1st January 2016)

• Record Type: Journal Article
• Authors: Chen, Hung-Shuo; Yu, Wan-Chin; Chang, Wei-Chen; Lu, Yen-Wei
• Is Part Of: Electrochimica acta. Volume 187(2016)
• Page Start: 655
• Page End: 661
• Publication Date: 2016-01-01
• Subjects: Zinc oxide -- Aggregates -- Dye-sensitized solar cell -- Light scattering; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.11.070
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Olive-shaped ZnO nanocrystallite aggregates were synthesized using an economical and environment-friendly aqueous-solution method. The submicron-sized hierarchical nanostructure is composed of highly crystalline ZnO nanoparticles about 20 nm in diameter and has an overall dimension of approximately 150 nm × 300 nm. We employed a low-temperature (150 °C for 1 h) thermal treatment process for the fabrication of bi-layer photoelectrode, with commercial ZnO nanoparticles (∼20 nm) as the under-layer and submicron-sized structures as the light-scattering over-layer. The N719-sensitized dye-sensitized solar cells incorporating the aggregate over-layer reached a higher power conversion efficiency of 4.43% than those incorporating a solid scatterer over-layer (3.57%). The enhanced overall conversion efficiency of aggregate-based cells was correlated with a prominent increase in the short-circuit current density. Optical and dye-loading investigations show that this improvement can be attributed to the dual functionality of the olive-shaped nanocrystallite aggregates, which have excellent light-scattering ability to enhance photon capture while providing a large surface area for sufficient dye adsorption.