Exciton-driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclusters
Abstract The fundamental bandgap E g of a semiconductor—often determined by means of optical spectroscopy—represents its characteristic fingerprint and changes distinctively with temperature. Here, we demonstrate that in magic sized II-VI clusters containing only 26 atoms, a pronounced weakening of...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2020-08-01
|
| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-020-17563-0 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850206185484976128 |
|---|---|
| author | Franziska Münzer Severin Lorenz Jiwoong Yang Taufik Adi Nugraha Emilio Scalise Taeghwan Hyeon Stefan Wippermann Gerd Bacher |
| author_facet | Franziska Münzer Severin Lorenz Jiwoong Yang Taufik Adi Nugraha Emilio Scalise Taeghwan Hyeon Stefan Wippermann Gerd Bacher |
| author_sort | Franziska Münzer |
| collection | DOAJ |
| description | Abstract The fundamental bandgap E g of a semiconductor—often determined by means of optical spectroscopy—represents its characteristic fingerprint and changes distinctively with temperature. Here, we demonstrate that in magic sized II-VI clusters containing only 26 atoms, a pronounced weakening of the bonds occurs upon optical excitation, which results in a strong exciton-driven shift of the phonon spectrum. As a consequence, a drastic increase of dE g/dT (up to a factor of 2) with respect to bulk material or nanocrystals of typical size is found. We are able to describe our experimental data with excellent quantitative agreement from first principles deriving the bandgap shift with temperature as the vibrational entropy contribution to the free energy difference between the ground and optically excited states. Our work demonstrates how in small nanoparticles, photons as the probe medium affect the bandgap—a fundamental semiconductor property. |
| format | Article |
| id | doaj-art-e33292bd4c844f4a9e17e51bcdfbcdc0 |
| institution | OA Journals |
| issn | 2041-1723 |
| language | English |
| publishDate | 2020-08-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj-art-e33292bd4c844f4a9e17e51bcdfbcdc02025-08-20T02:10:54ZengNature PortfolioNature Communications2041-17232020-08-011111710.1038/s41467-020-17563-0Exciton-driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclustersFranziska Münzer0Severin Lorenz1Jiwoong Yang2Taufik Adi Nugraha3Emilio Scalise4Taeghwan Hyeon5Stefan Wippermann6Gerd Bacher7Werkstoffe der Elektrotechnik and CENIDE, Universität Duisburg-EssenWerkstoffe der Elektrotechnik and CENIDE, Universität Duisburg-EssenCenter for Nanoparticle Research, Institute for Basic Science (IBS)Max-Planck-Institut für EisenforschungMax-Planck-Institut für EisenforschungCenter for Nanoparticle Research, Institute for Basic Science (IBS)Max-Planck-Institut für EisenforschungWerkstoffe der Elektrotechnik and CENIDE, Universität Duisburg-EssenAbstract The fundamental bandgap E g of a semiconductor—often determined by means of optical spectroscopy—represents its characteristic fingerprint and changes distinctively with temperature. Here, we demonstrate that in magic sized II-VI clusters containing only 26 atoms, a pronounced weakening of the bonds occurs upon optical excitation, which results in a strong exciton-driven shift of the phonon spectrum. As a consequence, a drastic increase of dE g/dT (up to a factor of 2) with respect to bulk material or nanocrystals of typical size is found. We are able to describe our experimental data with excellent quantitative agreement from first principles deriving the bandgap shift with temperature as the vibrational entropy contribution to the free energy difference between the ground and optically excited states. Our work demonstrates how in small nanoparticles, photons as the probe medium affect the bandgap—a fundamental semiconductor property.https://doi.org/10.1038/s41467-020-17563-0 |
| spellingShingle | Franziska Münzer Severin Lorenz Jiwoong Yang Taufik Adi Nugraha Emilio Scalise Taeghwan Hyeon Stefan Wippermann Gerd Bacher Exciton-driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclusters Nature Communications |
| title | Exciton-driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclusters |
| title_full | Exciton-driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclusters |
| title_fullStr | Exciton-driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclusters |
| title_full_unstemmed | Exciton-driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclusters |
| title_short | Exciton-driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclusters |
| title_sort | exciton driven change of phonon modes causes strong temperature dependent bandgap shift in nanoclusters |
| url | https://doi.org/10.1038/s41467-020-17563-0 |
| work_keys_str_mv | AT franziskamunzer excitondrivenchangeofphononmodescausesstrongtemperaturedependentbandgapshiftinnanoclusters AT severinlorenz excitondrivenchangeofphononmodescausesstrongtemperaturedependentbandgapshiftinnanoclusters AT jiwoongyang excitondrivenchangeofphononmodescausesstrongtemperaturedependentbandgapshiftinnanoclusters AT taufikadinugraha excitondrivenchangeofphononmodescausesstrongtemperaturedependentbandgapshiftinnanoclusters AT emilioscalise excitondrivenchangeofphononmodescausesstrongtemperaturedependentbandgapshiftinnanoclusters AT taeghwanhyeon excitondrivenchangeofphononmodescausesstrongtemperaturedependentbandgapshiftinnanoclusters AT stefanwippermann excitondrivenchangeofphononmodescausesstrongtemperaturedependentbandgapshiftinnanoclusters AT gerdbacher excitondrivenchangeofphononmodescausesstrongtemperaturedependentbandgapshiftinnanoclusters |