|The world-class COPE and ANFF-Q analytical facilities are comprised of the following instrumentation:|
This instrument is a bench top FT-IR spectrometer that can handle both solid and liquid IR samples. Its working range is 7800-370cm-1, with a resolution of 0.5cm-1. The instrument is equipped with a Universal ATR accessory for attenuated total reflection fourier transform infrared spectroscopy.
The STA 6000 is a combined Thermogravimetric Analyser and Differential Scanning Calorimeter. Its SaTurnA sensor combines measurement of both sample and reference temperatures allowing measurement of heat flow into a sample ensuring a thermogravimetric analysis procedure. It can measure from 15oC to 1000oC per minute and can purge with both N2 and air.
The Diamond DSC is a power-compensation differential scanning calorimeter; the sample and reference pans are heated by two independent furnaces embedded in a temperature-controlled heat sink. It supports modulated temperature DSC, standard DSC and Hyper DSC (temperature gradient less than 300oC.)
This instrument measures the molecular weight and polydispersity according to the analyte's (macromolecule) size with reference to polystyrene standards. There are two sets of columns in this instrument; one set for a broad range of molecular weights (2,000 - 40,000,000, Mixed A columns) and the other set is high resolution for measuring low molecular weights to up to 30,000 (Mixed E columns). This instrument has two detectors, which can be run simultaneously, namely: refractive index and tunable absorption. Our standard solvent is THF and is operated at 40oC.
The suitability of a material for an electronic device is dependent in part on the redox potential. Electrochemistry and especially Cyclic Voltammetry (CV) are powerful methods for obtaining information about the redox potentials (and stability) and location of the energy levels of hole and electron transport materials. The electrochemical processes occur at the electrode-solution interface and the measurements are based on a linear scan of the applied potential at the working electrode using a triangular potential waveform; the current response is measured and plotted against the applied potential. The HOMO and LUMO levels of the compound can be calculated from the oxidation and reduction potentials respectively (the gap between the first oxidation wave and the reduction wave provide the HOMO-LUMO energy difference.) Electronic changes induced as a result of structural modification of molecules can be detected and this allows prediction of synthetic strategies to further fine tune materials.
This instrument allows determination of sample melting point, melting range and boiling point up to 400oC with high measuring accuracy. The apparatus is designed to be operated with ease, featuring a large sample observation window and intuitive control buttons, as well as high speed heating (20oC/min) and fan cooling to assist in rapid acquisition of data. The device also has built in memory for 10 methods as well as RS-232 communication interface and capability of data transfer via PC software.
The Cary 5000 combines unparalleled Cary performance with Varian's innovative PbSmartTM technology, extending the wavelength range into the NIR to 3300 nm. The Cary 5000 can be used to achieve significant performance breakthroughs across a range of applications - from quantifying out-of-band blocking characteristics of band pass filters to measuring the high transmission of next generation fibre optic materials. The Cary 5000 is also an ideal reference instrument that can be used to check the performance of the other UV-Vis or NIR spectrophotometers.
Cary 5000 design features include:
The unit allows spin coating of organic materials onto an appropriate substrate e.g. glass, silicon, PDMS. A vacuum chuck holds the substrate coated with solutions of material which is then spun at precise speeds for controlled periods of time. The device is capable of spinning speeds up to 9999 rpm for 999 s. By modulating the spinning speed and duration, the thickness of the films being cast can be varied to best suit the application under scrutiny. The user can also control the ramp-up and ramp-down time allowing complete control over the spinning conditions for the full duration of the spin cycle.
The Dektak is used to measure the thickness or roughness of thin films, in the nanometer range with high repeatability. The Dektak has a large stage where a sample is placed underneath a stylus. The stage has an X-Y movement of approximately 2 inches. A 640 x 480-pixel (1/3 inch format) USB video camera is fitted with a fixed magnification, with an adjustable light source to help when viewing samples with different reflectivity. The stylus has a diamond tip which is moved over the surface of a material electromechanically taking measurements of the sample moving underneath it. As the sample is moved the stylus is moved over the surface, making vertical movements. As it does this, an electrical signal corresponding to the vertical movement of the stylus is produced, allowing for measurement of film thickness/roughness. This method allows for highly accurate and reproducible measurements in two dimensions. This can take scans up to 55 millimetres in length and can accommodate for samples up to 4 inches in thickness. The Dektak can also be programmed to make a three dimensional map of a surface to allow for viewing of film roughness over an area of the film.
The PLQY is the ratio of the number of photons emitted to photons absorbed and is a measure of how luminescent an organic material is. A HeCd laser (IK series, manufactured by Kimmon) is used to excite the organic material, which is kept within an integrating sphere (manufactured by SphereOptics.) The emission from thin films is anisotropic and the internal scattering coating of the integrating sphere redistributes it, enabling a reliable measurement of the organic material's total emission. This experimental setup is an essential tool in the characterization of organic semiconductors and allows greater understanding of the factors that influence a material's capacity for light emission.
Solar simulators are specialised light sources that to good approximation have a similar irradiance to that of the sun. This allows for consistent characterization of a solar cell device's solar power conversion efficiency, which can reliably be compared to other research groups around the world. We have two solar simulators, one located in a clean room, where the output is beamed through a quartz window into a water and oxygen free nitrogen atmosphere, and the second is in a darkened optical lab, on top of an air cushioned optical table.
The time-of-flight (TOF) experiment is used to measure the mobilities of holes and electrons following photo excitation in semiconductors at different electric fields and temperatures. The experiment is a custom made system consisting of a 4ns pulsed multi-wavelength Nd:YAG laser from Quantel, a 2 GHz LeCroy Waverunner 6200 Oscilloscope, a 100V AvTech pulse generator and an Oxford Instruments liquid nitrogen cooled cryostat. The setup allows us to measure the charge transport in thin films of organic semiconductors at temperatures ranging from 77K - 320K under vacuum and inert gas conditions. The high time resolution and the employed techniques, for example the use of a charge-injection layer, enable us to measure even fairly thin films. A high voltage source will enable us in the near future to mesure very thick films as well.