Modelling Charge Transport in Organic Semiconductors

Abstract

The search for energy efficient materials is more important now than ithas ever been before. As such, computational models that investigate chargetransport properties of materials have grown into an incredibly vast field ofresearch. These models require knowledge of the structures that materialsform, along with their electronic structure characteristics.The primary focus of this work was to develop a model, based on anexisting model used for investigating protein structures, that would allowfor a large number of molecular morphologies to be generated. This modelallows for a full atomistic morphology to be generated (which is importantfor charge transport simulations) at a fraction of the computational cost ofconventional techniques by treating molecules as a series of rigid sections.The model has been validated using two well documented test case morphologies,the first, Buckminsterfulerene due to its spherical nature, and thesecond, hexane due to its flexibility. After validation the model has beenused to generate morphologies for a subset of dithiophene derivatives thatour industry sponsor was interested in. Charge transport simulations werethen performed on these morphologies and these are the key result of thisresearch. We have shown clear trends in how varying the composition of thesidechains of these dithiophene based molecules directly affects the mobilitiesthey exhibit and thus, that charge transport is incredibly sensitive tomorphology.

Date of Award	27 Jun 2017
Original language	English
Awarding Institution	University of Bath
Supervisor	Alison Walker (Supervisor)