Strong localization effects in the photoluminescence of transition metal dichalcogenide heterobilayers

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F21%3A00540945" target="_blank" >RIV/61388955:_____/21:00540945 - isvavai.cz</a>

Výsledek na webu

<a href="http://hdl.handle.net/11104/0318535" target="_blank" >http://hdl.handle.net/11104/0318535</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/2053-1583/abe363" target="_blank" >10.1088/2053-1583/abe363</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Strong localization effects in the photoluminescence of transition metal dichalcogenide heterobilayers

Popis výsledku v původním jazyce

The emergence of various exciton-related effects in transition metal dichalcogenides (TMDC) and their heterostructures has inspired a significant number of studies and brought forth several possible applications. Often, standard photoluminescence (PL) with microscale lateral resolution is utilized to identify and characterize these excitonic phenomena, including interlayer excitons (IEXs). We studied the local PL signatures of van der Waals heterobilayers composed of exfoliated monolayers of the (Mo, W)(S, Se)2 TMDC family with high spatial resolution (down to 30 nm) using tip-enhanced photoluminescence (TEPL) with different orders (top/bottom) and on different substrates. We evidence that in MoS2–WSe2 heterobilayers, other PL signals may appear near the reported energy of the IEX transitions, possibly interfering in the interpretation of the results. The extra signals are only observed locally in small areas where the topography looks distorted. We assign those signals to the PL of the individual monolayers, in which the exciton energy is altered by the local strains caused by the formation of blisters and nanobubbles, and the PL is extremely enhanced due to the decoupling of the layers. We prove that even a single nanobubble as small as 60 nm-hence not optically visible-can induce such a suspicious PL feature in the micro-PL spectrum of an otherwise flat heterobilayer. In contrast, a PL peak, which could be assigned to the interlayer exciton in MoS2-WSe2, is observed at ≈1.0 eV.

Název v anglickém jazyce

Strong localization effects in the photoluminescence of transition metal dichalcogenide heterobilayers

Popis výsledku anglicky

The emergence of various exciton-related effects in transition metal dichalcogenides (TMDC) and their heterostructures has inspired a significant number of studies and brought forth several possible applications. Often, standard photoluminescence (PL) with microscale lateral resolution is utilized to identify and characterize these excitonic phenomena, including interlayer excitons (IEXs). We studied the local PL signatures of van der Waals heterobilayers composed of exfoliated monolayers of the (Mo, W)(S, Se)2 TMDC family with high spatial resolution (down to 30 nm) using tip-enhanced photoluminescence (TEPL) with different orders (top/bottom) and on different substrates. We evidence that in MoS2–WSe2 heterobilayers, other PL signals may appear near the reported energy of the IEX transitions, possibly interfering in the interpretation of the results. The extra signals are only observed locally in small areas where the topography looks distorted. We assign those signals to the PL of the individual monolayers, in which the exciton energy is altered by the local strains caused by the formation of blisters and nanobubbles, and the PL is extremely enhanced due to the decoupling of the layers. We prove that even a single nanobubble as small as 60 nm-hence not optically visible-can induce such a suspicious PL feature in the micro-PL spectrum of an otherwise flat heterobilayer. In contrast, a PL peak, which could be assigned to the interlayer exciton in MoS2-WSe2, is observed at ≈1.0 eV.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

2D Materials

ISSN

2053-1583

e-ISSN

2053-1583

Svazek periodika

8

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

10

Strana od-do

025028

Kód UT WoS článku

000621895200001

EID výsledku v databázi Scopus

2-s2.0-85102562445