EP02.15.01 : First-Principles Theory for Understanding Excitons in Organic Semiconductors

10:30 AM–11:00 AM Apr 6, 2018 (America - Denver)

PCC North, 200 Level, Room 222 BC

Sahar Sharifzadeh1

1, Boston Univ, Boston, Massachusetts, United States

Organic semiconductors are promising optoelectronic materials with strong light absorption and excitonic effects. For these systems, the interplay between inter- and intra-molecular interactions results in a complex behavior of excitons that is not yet well-controlled in devices. Here, we utilize first-principles theory to understand the role of inter-molecular orientation on the nature and energy of excitons within ordered organic materials. For a series of acene derivatives in the bulk crystalline phase, highly accurate many-body perturbation theory calculations predict significant exciton binding energies and charge-transfer character, which can be controlled through solid-state morphology or change of conjugation length. Additionally, we investigate the role of inter-molecular vibrational interactions on the optoelectronic properties of PTCDI-based molecular wires. Using a density functional theory analysis, we demonstrate that strong inter-molecular interactions lead to distinct vibrational, electronic, and optical properties. Overall, this work suggests a new strategy for design of new electronic and organic optoelectronic materials.