Structural and excited-state properties of oligoacene crystals from first principles
Journal article, 2016

Molecular crystals are a prototypical class of van der Waals (vdW) bound organic materials with excited-state properties relevant for optoelectronics applications. Predicting the structure and excited-state properties of molecular crystals presents a challenge for electronic structure theory, as standard approximations to density functional theory (DFT) do not capture long-range vdW dispersion interactions and do not yield excited-state properties. In this work, we use a combination of DFT including vdW forces, using both nonlocal correlation functionals and pairwise correction methods, together with many-body perturbation theory (MBPT) to study the geometry and excited states, respectively, of the entire series of oligoacene crystals, from benzene to hexacene. We find that vdW methods can predict lattice constants within 1% of the experimental measurements, on par with the previously reported accuracy of pairwise approximations for the same systems. We further find that excitation energies are sensitive to geometry, but if optimized geometries are used MBPT can yield excited-state properties within a few tenths of an eV from experiment. We elucidate trends in MBPT-computed charged and neutral excitation energies across the acene series and discuss the role of common approximations used in MBPT.

Author

T. Rangel

University of California

Lawrence Berkeley National Laboratory

Kristian Berland

University of Oslo

S. Sharifzadeh

Boston University

F. Brown-Altvater

Lawrence Berkeley National Laboratory

University of California

K. Lee

Lawrence Berkeley National Laboratory

Per Hyldgaard

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems Laboratory

L. Kronik

Weizmann Institute of Science

J. B. Neaton

University of California

Kavli Energy NanoSciences Institute

Lawrence Berkeley National Laboratory

Physical Review B

24699950 (ISSN) 24699969 (eISSN)

Vol. 93 11 115206

Areas of Advance

Nanoscience and Nanotechnology

Energy

Materials Science

Subject Categories

Physical Sciences

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1103/PhysRevB.93.115206

More information

Latest update

9/21/2018