Transient Absorption Spectrometer (TAS) is an instrument for femtosecond pump-probe spectroscopy. TAS incorporates highest quality optics, opto-mechanics, Fourier Transform spectrograph, optical chopper, vibration control, delay-line stage, and easy-to-use LabVIEW™-based software to deliver results. TAS can be upgraded and reconfigured to support many other ultrafast spectroscopy techniques as your research needs evolve.
• Technical specification with HR laser Pump: Same as HR laser (100 kHz, 1030 nm/515 nm, extended pump range with ultrashort pulses: 450-600 nm) Probes: white light (CaF2, Sapphire and LiF), terahertz probe (ZnTe: 0-3 THz GaP: 1-7 THz, 2 color laser induced plasma: 1-40 THz), Time resolution: ~6-10 fs
• Technical specification with SYLOS laser Pump: (1 kHz, 908 nm/454 nm)+THz pump (~150 kV/cm, @~1 THz) Probes: white light (CaF2, Sapphire and LiF), terahertz probe (ZnTe: 0-3 THz GaP: 1-7 THz, 2 color laser induced plasma: 1-40 THz), Time resolution: ~6 fs
• Technical specification with Terahertz pump laser Pump: (1 kHz, 908 nm/515 nm)+THz pump(~150 kV/cm, @~1 THz) Probes: white light (CaF2, Sapphire and LiF), terahertz probe(ZnTe: 0-3 THz GaP: 1-7 THz, 2 color laser induced plasma: 1-40 THz), Time resolution: ~10 fs
• Fourier Transform Visible to MIR Spectrometer: Bruker Vertex 80: spectral range: 50000-600 cm-1, step scan capable, time resolution: 2.5 ns, synchronized with 100 kHz or 1 kHz laser system, spectral resolution: 0.06 cm-1
• Software: LabVIEW-based software (in-house developed) to obtain TA measurements + OPUS software for Vertex 80
• Sample: Temperature-controlled stirred liquid sample holder, solid sample holder, integrating sphere for solid samples, electrochemical cell for combined TA and electrochemical measurements
Gas phase reaction chamber (GPRC) for pump-probe spectroscopy is an instrument for performing photodissociation experiments and gas phase reactions at low pressures (~1x10-4 Torr). The chamber incorporates an pulsed Even-Lavie gas valve (Amsterdam Cantilever Piezo Valve ACPV2/ACPV3) as a source for high intensity supersonic beam (jet cooled molecules, 20 s gate up to 5 kHz), large capacity turbo molecular pump capable of handling corrosive gases (STP-IS2207c CF200, 2200 l/s N2, magnetically levitated, Edwards), pressure gauges, integrated optical breadboard and optics for combining XUV and visible/terahertz pulses, optics for collecting photofragment fluorescence, fiber optic probe for fluorescence monitoring and motorized vacuum-compatible mirror mounts for accurate alignment of pump and probe pulses. Additional ports are also available for external device mounting (e.g. mass spectrometer) and various feedthroughs.
With a custom-made sample holder and electrochemical cell we can combine electrochemical measurements with the above detailed transient absorption spectroscopy setup to perform UV-vis pump/visible probe ultrafast spectroelectrochemical measurements. We can carry out measurements under inert conditions (or different glass inlets) in both aqueous and non-aqueous media on any optically transparent electrode. With the above-listed laser parameters, it is possible to probe the effect of applied bias on the generation and annihilation of charge carriers in the electrode material. For further details on the technique please see the following publications:
J. Am. Chem. Soc. 2018, 140, 86−89 and ACS Energy Lett., 2019, 4, 702–708
A further combined setup is under development that uses electrochemistry with optical pump/THz probe spectroscopy. This spectroscopy is sensitive to the mobile and non-mobile nature of charge carriers in semiconductors.
General chemistry laboratory
The chemistry lab at ELI-ALPS is equipped to handle the basic chemical needs of users in terms of sample preparation and quality control. General sample cleaning protocols can be employed using a programmable drying oven, ultrasonic bath and plasma cleaner. More advanced equipment makes it also suited to the preparation of sensitive samples on the spot. An MBraun glovebox provides the necessary inert working conditions (oxygen and water free environment). Annealing of prepared samples is also possible up to 1200 °C in a Nabertherm L 5/12 programmable muffle furnace. We are equipped with a PGSTAT302N potentiostat/galvanostat, which enables advanced electrochemical measurements. It is equipped with an electrochemical impedance module and a small current module. We are also able to perform intensity modulated photocurrent spectroscopy (white and blue LED) with the current electrochemical setup.
• Technical specifications of PGSTAT302N: Potential range: +/- 10 V, Maximum current: +/- 2 A, Current ranges: 1 A to 10 nA (100 pA with ECD module), Potentiostat bandwidth: 1 MHz, Used software: NOVA