Working Group of Electronic Phenomena - Topics and Instrumentation

DC and AC electrical characteristics in the dark and under illumination in the temperature interval 10 - 400 K. Photoelectrical characteristics in the spectral range 200 - 800 nm. Measurements of photogeneration efficiency of high-resistivity films by the xerographic discharge method. Thin film transistor and solar cell characterization.

• Instrument:

• Variable sets of instruments (Keithley electrometers and stabilized power supply, xenon lamp and pulse xenon lamp, 0.25 m monochromator Jobin Yvon, radiometers EG & G 580, closed cycle helium refrigerator Displex Air Products with vacuum system).

Determination of charge carrier mobility, post-transit behaviour, space-charge and trapping effects, and quantum efficiency of photogeneration of free charge carriers in polymer films by transient photocurrent measurements (time-of-flight method) with nanosecond time resolution.

• Instruments:

• Nd YAG and dye laser ND-60 Continuum Corp. with doublers - pulse duration 3-5 ns, wavelength regions 550-740 nm and 270-370 nm, 1-5 mJ per pulse in UV region, about 30 mJ per pulse in the visible region, 200 mJ at 532 nm, 450 mJ at 1064 nm, 10 Hz repetition rate or single pulse capacity.
• Digitizing oscilloscope Hewlet-Packard 5410 B.

Characterization of photochromic and electroluminescent behaviour of organic solids including time resolution (in millisecond time resolution) and temperature dependences.

• Instrument:

• UV-VIS spectrometers equipped with high sensitivity detector head EG & G 585 and temperature controller (Haake H40/F6), self-made spectrometer for thermostimulated absorption.

Microwave photoconductivity in polymers, characterization of kinetics of photoinduced ion-pairs.

• Instrument:

• Ka-band microwave source, reflectance detection, Nd YAG and dye laser ND-60 (see above).
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Preparation of thin organic films. Multilayered sandwich films of various organic materials and metals deposited in vacuum; the film thickness controlled with a quartz crystal. Polymer films spin-coated from polymer solutions.

• Instrument:

• Spin coating, vacuum deposition facility, quartz crystal balance monitor, profilometer.

Preparation of nanoparticles by laser ablation.

• Instrument:

• Nd YAG laser (see above).