The Photoelectrochemistry of Assemblies of Semiconductor Nanoparticles at Interfaces

The application of photoelectrochemical methods presents the researcher with a powerful set of versatile tools by which photoactive materials, such as semiconductor quantum dots, at conductive interfaces may be interrogated. While the range of photoelectrochemical techniques available is quite large, it is surprising that very few have found their way into common usage within the nanoparticle community. Here a number of photoelectrochemical techniques and the principles upon which they are based are introduced. A short discussion on the criticality of ensuring the nanoparticles are reliably anchored to the substrate is followed by an introduction to the basic set of equipment required in order to enable the investigator to undertake such experiments. Subsequently the four techniques of transient photocurrent response to square wave illumination, photocurrent spectroscopy, intensity modulated photocurrent spectroscopy and intensity modulated photovoltage spectroscopy are introduced. Finally, the information that can be acquired using such techniques is provided with emphasis being placed on a number of case studies exemplifying the application of photoelectrochemical techniques to nanoparticles at interfaces, in particular optically transparent electrodes.