AI Article Synopsis
- Colloidal nanoplatelets (NPLs) are flat semiconductor particles that show interesting optical properties, but their behavior at different temperatures has raised questions.
- Researchers conducted experiments to explain that the distinct emission colors observed at low temperatures come from two types of NPLs: one uncharged and one charged.
- At low temperatures, charged NPLs emit brightly, but as temperatures rise above 160 K, nonradiative processes reduce this emission, clarifying previous mysteries about the photoluminescence of CdSe NPLs.
Article Abstract
Colloidal nanoplatelets (NPLs) are atomically flat, quasi-two-dimensional particles of a semiconductor. Despite intense interest in their optical properties, several observations concerning the emission of CdSe NPLs remain puzzling. While their ensemble photoluminescence spectrum consists of a single narrow peak at room temperature, two distinct emission features appear at temperatures below ∼160 K. Several competing explanations for the origin of this two-color emission have been proposed. Here, we present temperature- and time-dependent experiments demonstrating that the two emission colors are due to two subpopulations of uncharged and charged NPLs. We study dilute films of isolated NPLs, thus excluding any explanation relying on collective effects due to NPL stacking. Temperature-dependent measurements explain that trion emission from charged NPLs is bright at cryogenic temperatures, while temperature activation of nonradiative Auger recombination quenches the trion emission above 160 K. Our findings clarify many of the questions surrounding the photoluminescence of CdSe NPLs.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.nanolett.0c01707 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!