First-principles photoelectron spectroscopy in molecular solids from multiscale GW-BSE/MM embedding

Charge/exciton transport properties of organic semiconductors make these materials attractive for use in optoelectronic devices. Understanding how inter- and intra-molecular interactions affect, e.g., transport energy levels is vital for engineering new materials and devices. Computational studies aiming at quantitative predictions must reflect the interplay of molecular electronic structure and local- and meso-scale environment in realistic experimental and working conditions.
Here, we present a multiscale study of the photoemission spectra of MADN thin films using a first principle scheme consisting of Metropolis Monte Carlo-based simulated annealing, Many Body Green's Function Theory within the GW approximation, a QM/MM embedding procedure, and explicit treatment of electron-vibrational coupling. We discuss effects of disorder, quasiparticle corrections, and electrostatic embedding on spatially resolved HOMO levels. Predicted UPS signals are in excellent agreement with experiment.