Terahertz conductivity in nanoscaled systems: effective medium theory aspects

0440754 - FZÚ 2015 RIV GB eng J - Journal Article
Kužel, Petr - Němec, Hynek
Terahertz conductivity in nanoscaled systems: effective medium theory aspects.
Journal of Physics D-Applied Physics. Roč. 47, č. 37 (2014), s. 1-14. ISSN 0022-3727. E-ISSN 1361-6463
R&D Projects: GA ČR GA13-12386S
Institutional support: RVO:68378271
Keywords : photoconductivity * depolarization fields * nanostructures * charge transport * time-resolved
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 2.721, year: 2014

Ultrafast photoconductivity in nanostructured semiconductors is poorly understood on the microscopic level in many systems. The terahertz spectroscopy constitutes a suitable method to probe the nanoscopic motion of charges with a sub-picosecond time resolution. However, straightforward fitting of the raw terahertz conductivity spectra by the Drude-Smith model, which is abundantly used in the literature, has not lead to a significant advance in an in-depth understanding of these phenomena. In this paper we provide a general analytical description of the photoconductivity and transient transmission spectra, where the effects of depolarization fields are systematically disentangled from the local carrier response function for both percolated and non-percolated samples. Application of our formula to the retrieval of the carrier response function may help significantly in uncovering the nature of charge carrier transport at the nanoscale level in quite arbitrary nanostructured systems.
Permanent Link: http://hdl.handle.net/11104/0243847