Theoretical Investigation
of Organic Ligands on the
Surface Structure of InP Quantum Dots: Implications for Display Materials
with Enhanced Surface Stability
posted on 2023-11-22, 02:20authored byEunseog Cho, Junho Lee, Tae-Gon Kim, Won-Joon Son, Inkook Jang, Dae Sin Kim
InP
quantum dots (QDs) have emerged as a prominent luminescent
material for display applications owing to their tunable emissive
properties and reasonable stability attributed to nanoscale surface
characteristics. However, the surface structures of InP QDs remain
elusive primarily due to the influence of organic ligands that dynamically
interact with surface atoms, ultimately affecting the surface stability.
In this study, we comprehensively explore the structural features
and energetics of InP QD surfaces modified by carboxylate and phosphine
ligands, employing both slab and wedge models in theoretical investigations.
The carboxylate ligand exhibits diverse binding modes, including various
types of bidentates and even monodentates, on the surface of In atoms
and effectively stabilizes polar facets. Conversely, the phosphine
ligand acts as a stabilizer for the nonpolar facet. As a result, the
equilibrium shape of InP QDs is anticipated to comprise multiple facets,
unveiling the presence of the dominant (111) facet alongside the (100)
and (110) facets. To validate our theoretical predictions, we obtained
the projected shapes of the synthesized InP QDs using aberration-corrected
high-resolution scanning transmission electron microscopy. The experimental
observations confirm our modeling predictions, reinforcing the accuracy
of our findings.