Charge patching method for electronic structures and charge transports of organic and organic/inorganic mixed Nanostructures

Lin-Wang Wang, Principal Investigator

When constructed for device application, a nanostructure rarely works alone.  Free standing colloidal quantum dots or wires are often connected or blended with organic/biological molecules to provide structural supports and composite electronic, optical properties.  Understanding the electronic structures and carrier transports of such mixed systems, and the structure-to-property relationship is often at the heart of nanoscience applications.  Theoretical simulation plays a pivotal role in studying these problems.  However, current theoretical studies for the electronic structures and carrier transports for disordered organic molecules and polymers are mostly based on
phenomenological models, with parameters obtained from fitting, not direct measurement or ab initio calculations.

The goal of this project is to develop new methods to calculate the electronic structures, optical properties and charge transports of large organic, inorganic and organic/inorganic mixture systems.  This will extend our capability of calculating such systems with ab initio accuracy from a few hundred atoms to hundreds of thousands of atoms.  This project continues to develop the charge patching methods (CPM) for organic and inorganic systems.  It also develops other linear scaling methods, especially the linear scaling three dimensional fragment (LS3DF) method.  It studies the structure-to-property relationship for organic systems, ligand passivation of inorganic nanocrystals, organic/inorganic interfaces, large inorganic systems like nanocrystals and alloys.  For organic systems, it studies polymers and organic small molecules.  It studies the carrier transports in organic systems.  In the long term, we also plan to test the CPM for evaluating the non-bond interactions in force field models.