Changes of the absorption cross section of Si nanocrystals with temperature and distance

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F17%3A00482700" target="_blank" >RIV/61388963:_____/17:00482700 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/17:10367382

Výsledek na webu

<a href="https://www.beilstein-journals.org/bjnano/articles/8/231" target="_blank" >https://www.beilstein-journals.org/bjnano/articles/8/231</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3762/bjnano.8.231" target="_blank" >10.3762/bjnano.8.231</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Changes of the absorption cross section of Si nanocrystals with temperature and distance

Popis výsledku v původním jazyce

The absorption cross section (ACS) of silicon nanocrystals (Si NCs) in single-layer and multilayer structures with variable thickness of oxide barriers is determined via a photoluminescence (PL) modulation technique that is based on the analysis of excitation intensity-dependent PL kinetics under modulated pumping. We clearly demonstrate that roughly doubling the barrier thickness (from ca. 1 to 2.2 nm) induces a decrease of the ACS by a factor of 1.5. An optimum separation barrier thickness of ca. 1.6 nm is calculated to maximize the PL intensity yield. This large variation of ACS values with barrier thickness is attributed to a modulation of either defect population states or of the efficiency of energy transfer between confined NC layers. An exponential decrease of the ACS with decreasing temperature down to 120 K can be explained by smaller occupation number of phonons and expansion of the band gap of Si NCs at low temperatures. This study clearly shows that the ACS of Si NCs cannot be considered as independent on experimental conditions and sample parameters.

Název v anglickém jazyce

Changes of the absorption cross section of Si nanocrystals with temperature and distance

Popis výsledku anglicky

The absorption cross section (ACS) of silicon nanocrystals (Si NCs) in single-layer and multilayer structures with variable thickness of oxide barriers is determined via a photoluminescence (PL) modulation technique that is based on the analysis of excitation intensity-dependent PL kinetics under modulated pumping. We clearly demonstrate that roughly doubling the barrier thickness (from ca. 1 to 2.2 nm) induces a decrease of the ACS by a factor of 1.5. An optimum separation barrier thickness of ca. 1.6 nm is calculated to maximize the PL intensity yield. This large variation of ACS values with barrier thickness is attributed to a modulation of either defect population states or of the efficiency of energy transfer between confined NC layers. An exponential decrease of the ACS with decreasing temperature down to 120 K can be explained by smaller occupation number of phonons and expansion of the band gap of Si NCs at low temperatures. This study clearly shows that the ACS of Si NCs cannot be considered as independent on experimental conditions and sample parameters.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GC16-09745J" target="_blank" >GC16-09745J: Porozumění účinnosti luminiscence křemíkových kvantových teček</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Beilstein Journal of Nanotechnology

ISSN

2190-4286

e-ISSN

—

Svazek periodika

8

Číslo periodika v rámci svazku

Nov 6

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

9

Strana od-do

2315-2323

Kód UT WoS článku

000415308200001

EID výsledku v databázi Scopus

2-s2.0-85034224472