Layer-dependent Quasiparticle Electronic Structure of the P3HT:PCBM Interface from A First-Principles Substrate Screening $GW$ Approach

Abstract

A prototypical organic photovoltaic material is a heterojunction composed of the blend of regioregular poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C${}_{61}$-butyric acid methyl ester (PCBM). Microscopic understanding of the energy conversion mechanism in this system involves the relationship between the electronic structure and the atomistic geometry of P3HT:PCBM interfaces. In this work, the effect of the number of P3HT layers on the electronic structure of the P3HT:PCBM interface is studied by means of first-principles $GW$. We apply the substrate screening approach to accelerate such calculations and to better understand the many-body dielectric screening at the interface. The quasiparticle band gap of the entire interface is found to decrease as the number of P3HT layers increases. The gaps of the individual components of the interface are found to be smaller than their isolated counterparts, with strong dependence on the number of P3HT layers. Importantly, when comparing the system of P3HT:PCBM - where a single interface is present - and the system of P3HT:PCBM:P3HT, where an interface is formed on either side of PCBM, we find that the two systems exhibit very different quasiparticle energy level alignments. We discuss possible implications of our findings in related experiments. The observed trends in layer-dependent quasiparticle electronic structure of P3HT:PCBM interfaces provide computational insight into energy conversion pathways in these materials.

26 pages, 4 figures

References in corpus (22)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Optimized norm-conserving Vanderbilt pseudopotentials
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Optimization Algorithm for the Generation of ONCV Pseudopotentials
• BerkeleyGW: A Massively Parallel Computer Package for the Calculation of the Quasiparticle and Optical Properties of Materials and Nanostructures
• Renormalization of Molecular Electronic Levels at Metal-Molecule Interfaces
• An exchange functional that tests the robustness of the plasmon description of the van der Waals density functional
• Amine-Gold Linked Single-Molecule Junctions: Experiment and Theory
• The GW compendium: A practical guide to theoretical photoemission spectroscopy
• Truncation of Periodic Image Interactions for Confined Systems
• Quasiparticle and Optical Spectroscopy of Organic Semiconductors Pentacene and PTCDA from First Principles
• Renormalization of Molecular Quasiparticle Levels at Metal-Molecule Interfaces: Trends Across Binding Regimes
• Coulomb-hole summations and energies for GW calculations with limited number of empty orbitals: a modified static remainder approach
• Noise-induced quantum coherence drives photocarrier generation dynamics at polymeric semiconductor heterojunctions
• Electronic energy level alignment at metal-molecule interfaces with a GW approach
• Accurate description of charged excitations in molecular solids from embedded many-body perturbation theory
• Accelerating $GW$-Based Energy Level Alignment Calculations for Molecule-Metal Interfaces Using a Substrate Screening Approach
• Resonant hot charge-transfer excitations in fullerene-porphyrin complexes: a many-body Bethe-Salpeter study
• Quasiparticle Levels at Large Interface Systems from Many-body Perturbation Theory: the XAF-GW method
• Energy Level Alignment at Hybridized Organic-metal Interfaces: the Role of Many-electron Effects
• First-principles investigation of organic photovoltaic materials C${}_{60}$, C${}_{70}$, [C${}_{60}$]PCBM, and bis-[C${}_{60}$]PCBM using a many-body $G_0{W}_0$-Lanczos approach
• Dielectric embedding GW for weakly coupled molecule-metal interfaces

Cited by in corpus (1)

• Quasiparticle electronic structure of phthalocyanine:TMD interfaces from first-principles $GW$