Time-resolved pump-probe spectroscopic ellipsometry of cubic GaN, Part II: Absorption edge shift with gain and temperature effects

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2FCZ______%3A_____%2F23%3AN0000022" target="_blank" >RIV/CZ______:_____/23:N0000022 - isvavai.cz</a>
Result on the web
<a href="https://pubs.aip.org/aip/jap/article/134/7/075703/2907074/Time-resolved-pump-probe-spectroscopic" target="_blank" >https://pubs.aip.org/aip/jap/article/134/7/075703/2907074/Time-resolved-pump-probe-spectroscopic</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1063/5.0153092" target="_blank" >10.1063/5.0153092</a>

Result language
angličtina
Original language name
Time-resolved pump-probe spectroscopic ellipsometry of cubic GaN, Part II: Absorption edge shift with gain and temperature effects
Original language description
We recently published a study concerning femtosecond pump-probe absorption edge spectroscopy of cubic GaN (fundamental bandgap: 3.23 eV), resulting in the transient dielectric function. In the present study, we continue our investigations of those pump-probe measurements by determining the time-dependent transition energy at the Fermi-vector between the conduction and valence bands. The generation of electron-hole pairs by the 266 nm pump-beam (4.66 eV) shifts the absorption edge by approximate to 500 meV within 1 ps due to many-body effects like band-filling and bandgap renormalization. Modeling this ultra-fast change is achieved by converting the transition energies into free-carrier concentrations, assuming the electron contributions to be dominant. We consider the relaxation, recombination, and diffusion of those free-carriers as well as either an additional gain-recombination or temperature effects. This allows for describing the transition energies on short time scales. Both models yield similar values for the characteristic relaxation time (similar to 0.21 ps), recombination time (similar to 25 ps), and diffusion coefficient (similar to 1 cm(2)/s).
Czech name
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Czech description
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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
10302 - Condensed matter physics (including formerly solid state physics, supercond.)

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)

Publication year
2023
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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