Time-resolved pump-probe spectroscopic ellipsometry of cubic GaN, Part I: Determination of the dielectric function
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2FCZ______%3A_____%2F23%3AN0000021" target="_blank" >RIV/CZ______:_____/23:N0000021 - isvavai.cz</a>
Result on the web
<a href="https://pubs.aip.org/aip/jap/article/134/7/075702/2907073/Time-resolved-pump-probe-spectroscopic" target="_blank" >https://pubs.aip.org/aip/jap/article/134/7/075702/2907073/Time-resolved-pump-probe-spectroscopic</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1063/5.0153091" target="_blank" >10.1063/5.0153091</a>
Alternative languages
Result language
angličtina
Original language name
Time-resolved pump-probe spectroscopic ellipsometry of cubic GaN, Part I: Determination of the dielectric function
Original language description
An ultra-fast change of the absorption onset for zincblende gallium-nitride (zb-GaN) ( fundamental bandgap: 3.23 eV) is observed by investigating the imaginary part of the dielectric function using time-dependent femtosecond pump-probe spectroscopic ellipsometry between 2.9 and 3.7 eV. The 266 nm (4.66 eV) pump pulses induce a large electron-hole pair concentration up to 4 similar to 10(20) cm(-3), which shift the transition energy between conduction and valence bands due to many-body effects up to approximate to 500 meV. Here, the absorption onset increases due to band filling while the bandgap renormalization at the same time decreases the bandgap. Additionally, the absorption of the pumpbeam creates a free-carrier profile within the 605 nm zb-GaN layer with high free-carrier concentrations at the surface, and low concentrations at the interface to the substrate. This leads to varying optical properties from the sample surface (high transition energy) to substrate (low transition energy), which are taken into account by grading analysis for an accurate description of the experimental data. For this, a model describing the time- and position-dependent free-carrier concentration is formulated by considering the relaxation, recombination, and diffusion of those carriers. We provide a quantitative analysis of optical experimental data (ellipsometric angles. and.) as well as a plot for the time-dependent change of the imaginary part of the dielectric function.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2023
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Applied Physics
ISSN
0021-8979
e-ISSN
1089-7550
Volume of the periodical
134
Issue of the periodical within the volume
7
Country of publishing house
US - UNITED STATES
Number of pages
10
Pages from-to
75702 (1-10)
UT code for WoS article
001050275100005
EID of the result in the Scopus database
2-s2.0-85168614404