Suppressing Tail Emission from AgIn<sub>1-<i>x</i></sub>Ga<sub><i>x</i></sub>S<sub>2</sub>/AgGaS<sub>2</sub> Quantum Dots by GaI<sub>3</sub>-Assisted Interface Reinforcement.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40676965.
- Also identified by DOI 10.1021/acsnano.5c07418.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Heteroepitaxy of AgGaS<sub>2</sub> (AGS) or GaS<sub><i>x</i></sub> shells on AgIn<sub>1-<i>x</i></sub>Ga<sub><i>x</i></sub>S<sub>2</sub> (AIGS) quantum dots (QDs) enables narrow band-edge emission with a near-unity photoluminescence quantum yield (QY). While this outcome is attributed to the passivation of donor-acceptor pair states on the surface, persistent tail emission, regardless of the QY, implies underlying interfacial defects in the AIGS/AGS QDs. Herein, we identify the latent compositional and crystallographic disorder at the core-shell interface originating from the surface instability of AIGS QDs. The strong coordination of oleylamine to group III cations promotes partial dissolution of the AIGS cores, resulting in a Ga-deficient, structurally disordered phase that contains interfacial donor states that are thermally mixed with the band-edge electron state. The incorporation of GaI<sub>3</sub> weakens the coordination of oleylamine to cations at the surface and in the dissolution products, thereby suppressing the disorder by fostering a Ga-rich environment. The suppressed tail emission, even at 80 K, highlights the importance of surface stabilization in eliminating the interfacial defects.