CAESR Facility

We perform our research at the Centre for Advanced Electron Spin Resonance (CAESR) in the Department of Chemistry led by Prof. Christiane Timmel and Prof. Arzhang Ardavan. Within CAESR, we have access to state-of-the-art EPR spectrometers operating at X-, Q- and W-band as well as several light sources for photoexcitation, including a wavelength-tuneable OPO covering the UV, visible and NIR region. For further details, see below or visit the CAESR webpage.

X-band continuous-wave EPR

Bruker EMX micro X-band continuous-wave EPR spectrometer with super high sensitivity (SHQE) resonator and ESR900 continuous-flow cryostat for operation at temperatures between 4 K and 300 K.

X/Q-band continuous-wave and pulse EPR

Bruker ElexSys E580 X/Q-band spectrometer

Bruker ElexSys E580 X- and Q-band EPR spectrometer with SpinJet arbitrary waveform generator (AWG), 1 kW X-band TWT and 140 W Q-band TWT. An Oxford Instruments CF935 cryostat enables measurements in the temperature range between 2 K and 300 K.

At X-band, the Bruker MD5, MD4, MS3 and MS2 resonators are available. At Q-band, the Bruker EN 5107D2 and ER 5106QT resonators are available, as well as a home-built Q-band resonator with large sample access and optical window for continuous-wave and pulse EPR. The Bruker X-band MD4 resonators and all Q-band resonators can be used for ENDOR experiments.

X/W-band continuous-wave and pulse EPR

Bruker ElexSys E680 X- and W-band EPR spectrometer with SpinJet arbitrary waveform generator (AWG) and 1 kW X-band TWT. Oxford Instruments cryostats enable measurements in the temperature range between 2 K and 300 K at both X- and W-band.

At X-band, Bruker MD5, MD4 and MS3 resonators are available. At W-band, a Bruker EN600-1021H TeraFlex W-band pulsed ENDOR resonator is available.

Optical excitation for EPR

An EKSPLA NT230 series tuneable diode-pumped laser system covering the wavelength range from 210 nm to 2600 nm is available for direct or fibre-coupled excitation of samples in the EPR resonator. The laser operates at a repetition rate of 50 Hz.

Xe arc lamp and halogen lamp sources are available for measurements under continuous white light illumination.

Electrically Detected Magnetic Resonance

We implemented EDMR detection on the available spectrometers with a custom-built transimpedance amplifier optimised for EDMR. The devices investigated by EDMR are contacted and connected to the amplifier through cables fed through the sample holder.

Sample preparation facilities

We also have access to facilities for sample preparation and solar cell fabrication, including a glove box, vacuum line, spin coater and home-built probe station for electrical characterisation of samples for EDMR spectroscopy.