Barrier-dependent photoluminescence of silicon nanocrystals in quadlayer samples: Inter-layer Si diffusion or excitonic energy transfer?

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F24%3A10489177" target="_blank" >RIV/00216208:11320/24:10489177 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=1H8xY82Bwq" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=1H8xY82Bwq</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.tsf.2024.140456" target="_blank" >10.1016/j.tsf.2024.140456</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Barrier-dependent photoluminescence of silicon nanocrystals in quadlayer samples: Inter-layer Si diffusion or excitonic energy transfer?

Popis výsledku v původním jazyce

In this work we studied photoluminescence (PL) of silicon nanocrystals (Si NCs) in multilayer samples fabricated from silicon rich oxynitride (SRON)/SiO2 superlattices. Unlike previously well-studied bilayer samples (i.e., pairs of NCs and barrier layers), here two different mean sizes of NCs were prepared in a special quadlayer configuration (i.e., smaller NCs / barrier / larger NCs / barrier). Furthermore, the barrier thicknesses were varied. When the barriers are decreasing from 4.6 nm to 1.8 nm, the PL band is demonstrated to be redshifting, whereas a PL contribution of small NCs is vanishing as expected assuming an exciton diffusion. However, we prove that this effect is related to inter-layer Si diffusion during sample fabrication, which is also a function of barrier thickness. Due to this fact, we registered a loss of luminescent centers in the sub-800 nm spectral range (small Si NCs in thin layers) when quadlayers in multilayer stacks are below a critical thickness. In fact, large Si NCs in thick SRON layers grow in expense of small ones in thin layers because the former have a larger capture crosssection for diffusing Si atoms. In this study we also probe PL of quadlayer samples under varied excitation powers (below and above saturation) and extract lifetime spectral dependencies from measured time-resolved decays in order to prove the above-mentioned nature of the PL.

Název v anglickém jazyce

Barrier-dependent photoluminescence of silicon nanocrystals in quadlayer samples: Inter-layer Si diffusion or excitonic energy transfer?

Popis výsledku anglicky

In this work we studied photoluminescence (PL) of silicon nanocrystals (Si NCs) in multilayer samples fabricated from silicon rich oxynitride (SRON)/SiO2 superlattices. Unlike previously well-studied bilayer samples (i.e., pairs of NCs and barrier layers), here two different mean sizes of NCs were prepared in a special quadlayer configuration (i.e., smaller NCs / barrier / larger NCs / barrier). Furthermore, the barrier thicknesses were varied. When the barriers are decreasing from 4.6 nm to 1.8 nm, the PL band is demonstrated to be redshifting, whereas a PL contribution of small NCs is vanishing as expected assuming an exciton diffusion. However, we prove that this effect is related to inter-layer Si diffusion during sample fabrication, which is also a function of barrier thickness. Due to this fact, we registered a loss of luminescent centers in the sub-800 nm spectral range (small Si NCs in thin layers) when quadlayers in multilayer stacks are below a critical thickness. In fact, large Si NCs in thick SRON layers grow in expense of small ones in thin layers because the former have a larger capture crosssection for diffusing Si atoms. In this study we also probe PL of quadlayer samples under varied excitation powers (below and above saturation) and extract lifetime spectral dependencies from measured time-resolved decays in order to prove the above-mentioned nature of the PL.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Thin Solid Films

ISSN

0040-6090

e-ISSN

1879-2731

Svazek periodika

803

Číslo periodika v rámci svazku

803

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

140456

Kód UT WoS článku

001275721200001

EID výsledku v databázi Scopus

2-s2.0-85199000290