National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Ultrafast response of electrons in nanostructured and disordered semiconductor systems studied by time-resolved terahertz spectroscopy
Zajac, Vít ; Kužel, Petr (advisor) ; Lloyd-Hughes, James (referee) ; Ostatnický, Tomáš (referee)
of Doctoral Thesis Title: Ultrafast response of electrons in nanostructured and disordered semiconductor systems studied by time-resolved terahertz spectroscopy Author: Vít Zajac Department / Institute: Institute of Physics of the Czech Academy of Sciences Supervisor of the doctoral thesis: doc. RNDr. Petr Kužel, Ph.D., Institute of Physics of the Czech Academy of Sciences Abstract: This thesis deals with charge transport in semiconducting nanomaterials on the picosecond time scale studied by time-resolved terahertz spectroscopy. The problematics of the effective response of composite materials is reviewed and the VBD effective medium model is formulated. The wave equation for the THz probing pulse propagating through inhomogeneously excited percolated and non-percolated semiconducting nanomaterials is solved. This theory is used to investigate charge transport in samples of nanoporous-Si-derived nanocrystals and in epitaxial Si nanocrystal superlattices. The experimental spectra are successfully modeled with the use of Monte Carlo calculations of charge carrier mobility in nanocrystals of corresponding sizes and degrees of percolation within the VBD approximation. It is found that nanocrystals from different regions of the nanocrystal size distribution of the sample dominate the signal in THz and...
Historic Mortars - HMC 2010 and RILEM TC 203-RHM final workshop
Válek, Jan ; Groot, C. ; Hughes, J.
The HMC2010 conference and TC 203-RHM final workshop took place in Prague 22-24 September 2011. The event was organised by the Institute of Theoretical and Applied Mechanics of the Academy of Sciences of the Czech Republic (ITAM AV ČR) in cooperation with RILEM. The conference was chaired by J. Válek of ITAM. The final workshop was chaired the TC 203-RHM chairman and its secretary C. Groot of TÚ Delft and J. Hughes of University of the West of Scotland. Members of the TC 203-RHM were acting also as the International Scientific Committee members of the conference. The HMC2010 Organising Committee was composed of the staff members of ITAM AV ČR. The event was attended by 190 participants from 30 countries. Such a number of participants was regarded as a great success considering its rather narrow and specific scope and also the fact that it was only the 2nd conference in this future to be regular series.