Accelerating $GW$-Based Energy Level Alignment Calculations for Molecule-Metal Interfaces Using a Substrate Screening Approach

Abstract

The physics of electronic energy level alignment at interfaces formed between molecules and metals can in general be accurately captured by the \emph{ab initio} $GW$ approach. However, the computational cost of such $GW$ calculations for typical interfaces is significant, given their large system size and chemical complexity. In the past, approximate self-energy corrections, such as those constructed from image-charge models together with gas-phase molecular level corrections, have been used to compute level alignment with good accuracy. However, these approaches often neglect dynamical effects of the polarizability and require the definition of an image plane. In this work, we propose a new approximation to enable more efficient $GW$-quality calculations of interfaces, where we greatly simplify the calculation of the non-interacting polarizability, a primary bottleneck for large heterogeneous systems. This is achieved by first computing the non-interacting polarizability of each individual component of the interface, e.g., the molecule and the metal, without the use of large supercells; and then using folding and spatial truncation techniques to efficiently combine these quantities. Overall this approach significantly reduces the computational cost for conventional $GW$ calculations of level alignment without sacrificing the accuracy. Moreover, this approach captures both dynamical and nonlocal polarization effects without the need to invoke a classical image-charge expression or to define an image plane. We demonstrate our approach by considering a model system of benzene at relatively low coverage on aluminum (111) surface. Although developed for such interfaces, the method can be readily extended to other heterogeneous interfaces.

References in corpus (11)

• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Renormalization of Molecular Electronic Levels at Metal-Molecule Interfaces
• Mechanically-Controlled Binary Conductance Switching of a Single-Molecule Junction
• Truncation of Periodic Image Interactions for Confined Systems
• Renormalization of Molecular Quasiparticle Levels at Metal-Molecule Interfaces: Trends Across Binding Regimes
• Environmentally-Sensitive Theory of Electronic and Optical Transitions in Atomically-Thin Semiconductors
• Relating Energy Level Alignment and Amine-Linked Single Molecule Junction Conductance
• First-Principles Approach for Energy Level Alignment at Aqueous Semiconductor Interfaces
• Energy Level Alignment at Molecule-Metal Interfaces from an Optimally-Tuned Range-Separated Hybrid Functional
• Energy Level Alignment at Hybridized Organic-metal Interfaces: the Role of Many-electron Effects