Chemical characterisation of organic semiconductors is essential to ensure purity and to be able to develop structure property relationships. In addition to the instruments already available on Campus such as Mass Spectrometer, cyclo voltametry, Electron Paramagnetic Resonance, and Neutron Magnetic Resonance, the OSC has available:

Gel Permeation Chromatography - Light Scattering

For the characterisation of polymers, the OSC has a Gel Permeation Chromatography (GPC) setup from Polymer Laboratories combined with static and dynamic light scattering from Precision Detectors. The absolute molecular weight and sizes down to a few nanometers can then be precisely determined which allows us to optimise the synthesis of conjugated polymers to produce a narrow band of molecular weights.

Magnetic Resonance

Precessing Spin in a magnetic field.

Electron Spin Resonance (ESR) is a spectroscopic technique that uses the interaction of microwave or millimetre-wave radiation with unpaired electrons in an applied magnetic field to yield information on the structure and constituents of a range of systems. It may be applied to a very wide range of problems, from the characterisation of spin defects in semiconductors to the determination of protein structure. This technique is also an asset for the observation of radical reactions and is particularly widely used in the biochemical sciences.

ESR instrument

The ESR group at St Andrews is part of the OSC and is specialised in high-field techniques and instrumentations, using fields of around 10 times those used in most commercial spectrometers. This specificity offers greater sensitivity and spectral resolution which is of particular interest for the study of new materials. Our main spectrometer, developed in St-Andrews, is a continuous wave system operating mainly at 90GHz, but also at 180 and 270 GHz. We are currently constructing a high power pulsed 90GHz spectrometer and will shortly be taking delivery of a 10GHz commercial pulsed system.