This is the second workshop on Transient Current Technique, with the first one being held at DESY in 2015 ( https://indico.desy.de/conferenceDisplay.py?confId=12934 ).
Transient Current Technique is becoming one of the key techniques in sensor characterization and qualification and has gained a lot of users in recent years. With Two Photon Absorption TCT on the horizon, the future of TCT certainly remains bright.
The workshop is dedicated to the exchange of information and experience in TCT. It covers all the aspects of operation:
-analysis software and ways to extract different sensor information from measurements
-simulation of measurements
A speciality of the workshop is the laboratory exercise part where hands-on experience can be gained. The second workshop has extended the topic also to the most recent findings obtained from TCT measurements on different devices.
Oganizing committee Vladimir Cindro , Jožef Stefan Institute
Hendrik Jansen , DESY Andrej Gorišek, Jožef Stefan Institute
Gregor Kramberger, Jožef Stefan Institute
Susanne Kühn, Unviersity of Freiburg & CERN
Igor Mandić, Jožef Stefan Institute
Marko Mikuž, Jožef Stefan Institute & University of Ljubljana
Sven Wonsak, University of Liverpool
Marko Zavrtanik, Jožef Stefan Institute
Resolving authentic time dependence of time-of-flight photocurrent in organic semiconductors
Time-of-flight photoconductivity (TOF) is a powerful method, which is used to study conversion of photons to electrons and their transport through thin organic semiconductor layers. Compared to current-voltage characterization methods, TOF results are unaffected by the spurious effects at the semiconductor/metal interfaces. Precise knowledge of photocurrent time-dependence is of crucial importance for the determination of charge transport parameters such as mobility and the width of charge transporting states. Our TOF measurements of single-crystals of dioctyl-benzothieno-benzothiophene (C8-BTBT) show that transport of photexcited carriers and the corresponding photocurrent across two coplanar metal contacts separated by 120 µm, occurs in a fraction of a microsecond. However, measured time-dependent photocurrent (I(t)), compared to theoretical predictions, showed additional peaks and significant broadening of the I(t) lineshape. We found that additional peaks correspond to signal reflections from the waveguide terminations. And peaks broadening occurs due to 3-ns duration of the photoexcitation laser. Direct deconvolution of the measured signal was not possible due to signal reflections and relatively high noise-to-signal ratio. Therefore we estimated a time dependence of the photocurrent, which reproduced the measured signal transient. Estimated I(t) was considered as an authentic TOF response of the material under investigation.