Classical Force Field Parameters for InP and InAs Quantum Dots with Various Surface Passivations

Area of Science:

• Materials Science
• Computational Chemistry
• Nanotechnology

Background:

• Accurate simulation of colloidal quantum dot (QD) surface chemistry is crucial for understanding nanocrystal behavior.
• Classical molecular dynamics (MD) simulations are often limited by the lack of appropriate force field (FF) parameters for QD-ligand interfaces.

Purpose of the Study:

• To develop and validate accurate force field (FF) parameters for Indium Phosphide (InP) and Indium Arsenide (InAs) quantum dots (QDs).
• To enable classical MD simulations of QD systems with various organic ligands in explicit solvents.

Main Methods:

• Utilized a stochastic optimization algorithm to derive FF parameters for InP and InAs QDs with Cl, amine, carboxylate, and thiolate ligands.
• Interfaced the new QD FF parameters with existing FF for organic molecules.
• Validated the FF parameters by comparing classical MD simulations with *ab initio* MD, experimental, and theoretical data.

Main Results:

• Successfully obtained and interfaced FF parameters for InP and InAs QDs with common capping ligands.
• Developed a method to simulate InP and InAs QDs with diverse organic ligands in apolar solvents using classical MD.
• Demonstrated good agreement between classical MD simulations using the new parameters and reference data.

Conclusions:

• The developed FF parameters significantly improve the accuracy of classical MD simulations for colloidal InP and InAs QDs.
• This work provides a valuable tool for studying the surface chemistry and interfacial behavior of quantum dots.