Preconditioning for a Phase-Field Model with Application to Morphology Evolution in Organic Semiconductors

TL;DR

This paper introduces a preconditioning strategy for efficiently solving a complex phase-field model describing morphology evolution in organic semiconductors, aiding in the simulation of organic solar cell performance.

Contribution

It presents a novel preconditioning method for large-scale linear systems arising from a coupled fourth-order PDE model in organic semiconductor morphology simulations.

Findings

Preconditioning improves computational efficiency and robustness.

Method effectively handles parameter variations.

Enables detailed morphology and charge transport analysis.

Abstract

The Cahn--Hilliard equations are a versatile model for describing the evolution of complex morphologies. In this paper we present a computational pipeline for the numerical solution of a ternary phase-field model for describing the nanomorphology of donor--acceptor semiconductor blends used in organic photovoltaic devices. The model consists of two coupled fourth-order partial differential equations that are discretized using a finite element approach. In order to solve the resulting large-scale linear systems efficiently, we propose a preconditioning strategy that is based on efficient approximations of the Schur-complement of a saddle point system. We show that this approach performs robustly with respect to variations in the discretization parameters. Finally, we outline that the computed morphologies can be used for the computation of charge generation, recombination, and transport in organic solar cells.