OBJECTIVE 01
Predictive Emission Modelling
Predict emission energies, radiative properties, and excited-state character across chemically diverse OLED emitters.
Research Overview
Organic light-emitting diodes (OLEDs) provide a unique platform in which fundamental excited-state chemistry directly determines device performance.
My previous research has focused on understanding the photophysics and stability of molecular materials used in OLEDs, particularly phosphorescent transition-metal complexes and organic host materials.
Building on this foundation, my future research will progress towards thermally activated delayed fluorescence (TADF) and radical-based OLEDs, with the long-term objective of developing predictive computational strategies for efficient and stable next-generation emitters.
Phosphorescent OLED Materials
My work on phosphorescent OLED materials established computational protocols for understanding emission in Pt(II) and Ir(III) complexes.
For Pt(II) phosphors, high-level coupled-cluster calculations and density-functional methods were benchmarked to accurately predict phosphorescence energies and identify the excited states involved in emission (Inorg. Chem. 2021, 60, 22, 17230–17240) .
In heteroleptic Ir(III) complexes, this approach was extended to characterise emissive states, phosphorescence rates, and vibronically resolved spectra (J. Phys. Chem. A 2023, 127, 34, 7241–7255) .
Together, these studies demonstrated that predictive modelling
of OLED materials requires an accurate description of the
complete excited-state landscape rather than consideration of
only a single optimised excited state.
Excited-State Degradation and Operational Stability
A second direction emerging from my previous work concerns excited-state degradation and operational stability .
I have explored static electronic-structure calculations, non-adiabatic dynamics, and active learning to identify degradation pathways in OLED host materials.
Building on this experience, my future research will investigate efficiency and stability simultaneously, determining how excited-state populations, molecular structure, and non-radiative dynamics lead to bond activation and irreversible chemical degradation.
Thermally Activated Delayed Fluorescence
The first extension of this programme will focus on thermally activated delayed fluorescence (TADF) .
TADF performance is controlled by the delicate interplay between singlet and triplet excited states, molecular reorganisation, spin–orbit coupling, intersystem crossing, reverse intersystem crossing, and non-radiative decay.
I will investigate these processes using electronic-structure calculations and non-adiabatic dynamics, with particular emphasis on understanding how conformational motion modifies excited-state energetics and kinetics.
The objective is to establish molecular design principles that
simultaneously optimise emission efficiency, colour, and
photochemical stability.
Radical-Based OLEDs
A complementary direction will target radical-based OLEDs, in which open-shell molecules provide access to emissive doublet states and fundamentally different photophysics from conventional fluorescent, phosphorescent, and TADF emitters.
Their theoretical description remains challenging because commonly used open-shell approaches can suffer from spin contamination and an inadequate treatment of excited-state configurations.
A major methodological objective will therefore be the development of computationally efficient and spin-pure approaches for open-shell excited states .
Spin-Pure Electronic-Structure Methods
This direction will build on methodological developments in my current postdoctoral group, including the Extended Restricted Open-Shell Pariser–Parr–Pople (ExROPPP) approach for rapidly calculating spin-pure excited states of organic radicals.
I aim to extend the underlying principles of spin adaptation towards chemically more diverse radical emitters, including substituted, heteroatom-containing, and larger conjugated systems relevant to OLED applications.
These methods will be benchmarked against coupled-cluster and multireference calculations, with the aim of bridging the gap between high-level electronic-structure theory and computationally inexpensive models suitable for screening large molecular libraries.
Machine-Learning Potentials for Excited-State Dynamics
Automated high-throughput workflows will generate accurate excited-state energies, gradients, electronic couplings, and molecular configurations to train machine-learning potentials for excited-state dynamics .
Active learning and uncertainty-aware sampling will reduce the amount of expensive quantum-chemical data required, while machine-learning potentials will enable non-adiabatic simulations over larger configurational and temporal scales.
This framework will be applied across phosphorescent, TADF, and radical emitters to understand relaxation, state crossing, emission, and degradation within a common theoretical framework.
Computational Framework
- Density-functional and time-dependent density-functional theory
- Coupled-cluster excited-state methods
- Multireference electronic-structure calculations
- Spin-pure open-shell excited-state methods
- Non-adiabatic molecular dynamics
- Active learning and uncertainty-aware sampling
- Machine-learning potentials
- Automated high-throughput computational workflows
Principal Research Objectives
OBJECTIVE 02
Stability and Degradation
Identify the electronic and structural origins of non-radiative decay, bond activation, and irreversible molecular degradation.
OBJECTIVE 03
Spin-Pure Radical Methods
Develop computationally efficient approaches for describing open-shell excited states without severe spin contamination.
OBJECTIVE 04
Data-Driven Molecular Discovery
Combine quantum chemistry, molecular dynamics, automation, and machine learning to screen and design next-generation molecular emitters.
Long-Term Research Vision
Ultimately, quantum chemistry, spin-pure excited-state methodology, non-adiabatic dynamics, and machine learning will be integrated into a data-driven molecular-discovery platform.
The long-term goal is to progress from explaining the behaviour
of existing OLED materials to predicting and designing emitters
that simultaneously achieve favourable emission energies, high
radiative efficiency, controlled excited-state dynamics, and
enhanced operational stability.