Highly Porous and Novel 1D-TiO2 Nanoarchitecture with Light Harvesting Morphology for Photovoltaic Applications

Abstract

A novel photoanode architecture revamped by dandelion-like TiO2 (DS) structures as light harvesting ingredients over the vertically oriented TiO2 nanowire (NW) bunches has been prepared on FTO glass without any seed layer through a single-step solvothermal process. High Resolution SEM observations showed that the synthesized photoanode consists of dandelion-like structures over vertically oriented nanowires with high surface porosity. Both the nanowire and dandelion structures possess rutile TiO2 crystal phase as confirmed with XRD analysis which also revealed that the nanoarchitecture is single crystalline, an essential condition for faster electron transport at the interfaces. The enhanced light harvesting capabilities and bandgap were examined using UV-DRS. Field dependent dark and photo conductivity measurements were performed to observe the response of the material to the visible spectrum. The proposed photoanode incorporating 1D-TiO2 electron transporters provides a novel configuration for improved light harvesting application. Introduction. Demand for energy finds first place in the list of humanity's top ten problems to be faced in the next 50 years [1]. The biggest challenge of our modern society is to find and replace the gradually vanishing conventional energy resources by renewable energy resources and at the same time ensuring safety, cleanliness and eco-friendly approach. Among the various sources of renewable energy known so far, solar energy is considered to assume the role of sustainable future energy. Dye Sensitized Solar Cell (DSSC) is a low cost and ecofriendly technology for the conversion of sunlight into electricity [2]. Nanostructured Titanium dioxide (TiO2) has attracted growing interest in DSSCs on account of its unique structure and properties [3]. The maximum power conversion efficiency in DSSCs reported so far 13% has been achieved by incorporating nanostructured Titanium dioxide (TiO2) [4]. The performance of these cells depend much on the shape and morphology of the TiO2 photoanode.