Quantum behavior of terahertz photoconductivity in silicon nanocrystals networks

0474043 - FZÚ 2018 RIV US eng J - Journal Article
Pushkarev, Vladimir - Ostatnický, T. - Němec, Hynek - Chlouba, T. - Trojánek, F. - Malý, P. - Zacharias, M. - Gutsch, S. - Hiller, D. - Kužel, Petr
Quantum behavior of terahertz photoconductivity in silicon nanocrystals networks.
Physical Review B. Roč. 95, č. 12 (2017), s. 1-9, č. článku 125424. ISSN 2469-9950. E-ISSN 2469-9969
R&D Projects: GA ČR GA17-03662S
EU Projects: European Commission(XE) 607521 - NOTEDEV
Institutional support: RVO:68378271
Keywords : terahertz spectroscopy * charge transport * silicon nanocrystals * linear response theory
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.813, year: 2017

Quantum-size effects are essential for understanding the terahertz conductivity of semiconductor nanocrystals, particularly at low temperatures. We derived a quantum mechanical expression for the linear terahertz response of nanocrystals, its introduction into an appropriate effective medium model provides a comprehensive microscopic approach for the analysis of terahertz conductivity spectra as a function of frequency, temperature, and excitation fluence. We performed optical pump–terahertz probe experiments in multilayer Si quantum dot networks with various degrees of percolation at 300 and 20 K and with variable pump fluence. Our theoretical approach was successfully applied to quantitatively interpret all the measured data within a single model. A careful data analysis made it possible to assess the distribution of sizes of nanocrystals participating to the photoconduction.
Permanent Link: http://hdl.handle.net/11104/0271142