Dye sensitized solar cells (DSSC) are inspired by photosynthesis. The main components of a DSSC are a dye that absorbs photons from the sun and injects its excited electron into a wide-band-gap semiconductor that channels the resulting electron through an electric circuit. Titanium dioxide (TiO2) has been widely used as a semiconductor material for DSSCs, typically using a mixture of the anatase and rutile crystalline phases. The chemisorption of the dye to the TiO2 surface will greatly affect the efficiency of the DSSC. The aim of this project is to use Raman spectroscopy to investigate the interface between the semiconductor and the dye sensitizer. We have found that if the monochromatic light sources used in Raman have a high enough laser power, the transition from the pure anatase phase to the rutile phase can be induced. This phenomenon will be studied in detail by adsorbing different dyes, with different anchoring groups (carboxylic and sulfonic groups) onto the TiO2 anatase surface. In addition, Raman spectroscopy is used to create a calibration curve by preparing different standard mixtures with different percentages of the anatase and rutile phase, ranging from 0-100%, allowing us to quantify the amount of rutile created during this induced phase transition.

A Raman spectroscopic study of the anatase to rutile phase transition of TiO2 induced by photoexcitation of adsorbed dyes

256th National Meeting (2018)

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