Electronic Band Structure and Optical Properties of HgPS3 Crystal and Layers

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F24%3A43929977" target="_blank" >RIV/60461373:22310/24:43929977 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.acs.org/doi/full/10.1021/acs.jpcc.4c00562" target="_blank" >https://pubs.acs.org/doi/full/10.1021/acs.jpcc.4c00562</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcc.4c00562" target="_blank" >10.1021/acs.jpcc.4c00562</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Electronic Band Structure and Optical Properties of HgPS3 Crystal and Layers

Popis výsledku v původním jazyce

Transition metal thiophosphates (MPS3) are of great interest due to their layered structure and magnetic properties. Although HgPS3 may not exhibit magnetic properties, its uniqueness lies in its triclinic crystal structure and in the substantial mass of mercury, rendering it a compelling subject for exploration in terms of fundamental properties. In this work, we present comprehensive experimental and theoretical studies of the electronic band structure and optical properties for the HgPS3 crystal and mechanically exfoliated layers from a solid crystal. Based on absorption, reflectance and photoluminescence measurements supported by theoretical calculations, it is shown that the HgPS3 crystal has an indirect gap of 2.68 eV at room temperature. The direct gap is identified at the Gamma point of the Brillouin zone (BZ) approximate to 50 meV above the indirect gap. The optical transition at the Gamma point is forbidden due to selection rules, but the oscillator strength near the Gamma point increases rapidly and therefore the direct optical transitions are visible in the reflectance spectra approximately at 60-120 meV above the absorption edge, across the temperature range of 40 to 300 K. The indirect nature of the bandgap and the selection rules for Gamma point contribute to the absence of near-bandgap emission in HgPS3. Consequently, the photoluminescence spectrum is primarily governed by defect-related emission. The electronic band structure of HgPS3 undergoes significant changes when the crystal thickness is reduced to tri- and bilayers, resulting in a direct bandgap. Interestingly, in the monolayer regime, the fundamental transition is again indirect. The layered structure of the HgPS3 crystal was confirmed by scanning electron microscopy (SEM) and by mechanical exfoliation.

Název v anglickém jazyce

Electronic Band Structure and Optical Properties of HgPS3 Crystal and Layers

Popis výsledku anglicky

Transition metal thiophosphates (MPS3) are of great interest due to their layered structure and magnetic properties. Although HgPS3 may not exhibit magnetic properties, its uniqueness lies in its triclinic crystal structure and in the substantial mass of mercury, rendering it a compelling subject for exploration in terms of fundamental properties. In this work, we present comprehensive experimental and theoretical studies of the electronic band structure and optical properties for the HgPS3 crystal and mechanically exfoliated layers from a solid crystal. Based on absorption, reflectance and photoluminescence measurements supported by theoretical calculations, it is shown that the HgPS3 crystal has an indirect gap of 2.68 eV at room temperature. The direct gap is identified at the Gamma point of the Brillouin zone (BZ) approximate to 50 meV above the indirect gap. The optical transition at the Gamma point is forbidden due to selection rules, but the oscillator strength near the Gamma point increases rapidly and therefore the direct optical transitions are visible in the reflectance spectra approximately at 60-120 meV above the absorption edge, across the temperature range of 40 to 300 K. The indirect nature of the bandgap and the selection rules for Gamma point contribute to the absence of near-bandgap emission in HgPS3. Consequently, the photoluminescence spectrum is primarily governed by defect-related emission. The electronic band structure of HgPS3 undergoes significant changes when the crystal thickness is reduced to tri- and bilayers, resulting in a direct bandgap. Interestingly, in the monolayer regime, the fundamental transition is again indirect. The layered structure of the HgPS3 crystal was confirmed by scanning electron microscopy (SEM) and by mechanical exfoliation.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

<a href="/cs/project/LL2101" target="_blank" >LL2101: Příští Generace Monoelementárních 2D Materiálů</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Journal of Physical Chemistry C

ISSN

1932-7447

e-ISSN

1932-7455

Svazek periodika

128

Číslo periodika v rámci svazku

22

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

11

Strana od-do

9270-9280

Kód UT WoS článku

001233760600001

EID výsledku v databázi Scopus

2-s2.0-85194229287