Analytical extensions to the Gaussian Disorder Model for Organic Solar Cells

Abstract

This thesis presents a series of analytical extensions to the Gaussian Disorder Model, aimed
at improving the theoretical understanding of exciton and charge transport, and light-matter
interactions in organic solar cells. By deriving continuum limits of transport master equations,
we develop energy dependent models that explicitly account for the energetic disorder inherent
in organic solar cells, providing an advancement over conventional drift-diffusion approaches
which typically neglect this complexity. In addition to charge transport, we construct analogous
models for light-matter interaction and trap-assisted recombination, providing a more
comprehensive framework for describing the physical processes within disordered organic solar
cells. Numerical solutions to the resulting differential equations are obtained and analysed,
demonstrating consistency with expected physical behaviour and validating the robustness of
our approach, as well as opportunities for refinement. Finally, we propose several extensions
to this work, with the long-term goal of developing a complete, physically grounded model
of an organic solar cell that integrates optical generation and recombination, exciton diffusion
and dissociation, charge transport, and other recombination mechanisms within a unified
methodology based around the assumption of a Gaussian density of states.

Date of Award	9 Dec 2025
Original language	English
Awarding Institution	University of Bristol
Supervisor	Peter Green (Supervisor) & Sebastian Muller (Supervisor)