Sensitizers: Dyes and quantum dots

Abstract

Several approaches aimed at extending the spectral activity range of wide-band-gap semiconductors have been already reviewed in previous chapters of this book. In addition to structural modifications that may lead to different electronic effects, such as anionic or cationic doping and solid solution formation, there is a possibility of modifying the surface of the semiconductor with a substance that absorbs light energy and transfers it, under favourable conditions, to an otherwise photochemically inactive or less active substrate. This substance is referred to as photosensitizer.