Publications

Open-access versions are available from Apollo, the University of Cambridge repository. Full citation data can be found on Google Scholar.

Selected recent publications

Ultrafast spectroscopy and microscopy

Decoupling excitons from high-frequency vibrations in organic molecules

Ghosh et al., Nature (2024)

Coupling to carbon–carbon stretching vibrations was thought to be an unavoidable source of energy loss in organic light emitters. Broadband impulsive vibrational spectroscopy identified two molecular design rules that decouple excitons from these vibrations, giving efficient near-infrared emission.

Ultrafast spectroscopy and microscopy

Local symmetry breaking drives picosecond spin domain formation in polycrystalline halide perovskite films

Ashoka et al., Nature Materials (2023)

Femtosecond polarisation-resolved microscopy shows that light creates micrometre-scale spin domains within picoseconds in polycrystalline halide perovskite films. Local breaking of inversion symmetry drives the spin currents, suggesting a route to optically controlled spin devices that need no external magnetic field.

Ultrafast spectroscopy and microscopy

Efficient energy transport in an organic semiconductor mediated by transient exciton delocalization

Sneyd et al., Science Advances (2021)

Excitons usually travel less than about 50 nm in organic semiconductors. In highly ordered films of polymer nanofibres they travel up to 300 nm, two to three orders of magnitude faster, through a mechanism termed transient exciton delocalisation. The work sets out design criteria for materials with efficient energy transport.

Charge photometry

Avalanche-like intercalation and intraparticle correlations in graphite

Han et al., Nature (2026)

Graphite is the anode in almost every lithium-ion battery. Operando optical microscopy shows that lithium enters graphite particles in sudden, localised “avalanches”, explained by a model in which static disorder controls the dynamics.

Charge photometry

Operando optical tracking of single-particle ion dynamics in batteries

Merryweather et al., Nature (2021)

The paper that introduced charge photometry. Using visible light rather than X-rays or electron beams, it follows lithium ions moving into and out of individual electrode particles inside a working battery, and shows how phase transitions proceed during charge and discharge.

Charge photometry

Operando monitoring of single-particle kinetic state-of-charge heterogeneities and cracking in high-rate Li-ion anodes

Merryweather et al., Nature Materials (2022)

Charge photometry applied to an anode material designed for fast charging. At high rates, lithium distributes unevenly within individual particles, and these heterogeneities are linked to particle cracking, a cause of battery degradation.

Singlet fission

Direct observation of ultrafast singlet exciton fission in three dimensions

Ashoka et al., Nature Communications (2022)

An interferometric pump–probe microscope that tracks photoexcitations in three dimensions with sub-10 nm precision and 15 fs time resolution, used to follow singlet fission as it unfolds within pentacene crystals.

Singlet fission

Ligand-Directed Self-Assembly of Organic-Semiconductor/Quantum-Dot Blend Films Enables Efficient Triplet Exciton-Photon Conversion

Gray et al., Journal of the American Chemical Society (2024)

Designing the ligands on quantum dots controls how they assemble within organic semiconductor films. This enables efficient conversion of triplet excitons generated by singlet fission into emitted light, a key step towards photon-multiplier films for solar cells.

Organic–lanthanide nanoparticles

Triplets electrically turn on insulating lanthanide-doped nanoparticles

Yu et al., Nature (2025)

Lanthanide-doped nanoparticles emit sharp, stable near-infrared light but are electrical insulators. Attaching organic molecules that pass triplet excitons to the nanoparticles allows them to be switched on electrically, giving light-emitting diodes that operate at about 5 V.

Organic–lanthanide nanoparticles

Lanthanide-doped nanocrystals enable organic room-temperature phosphorescence in solution through direct triplet excitation

Zhu et al., Nature Chemistry (2026)

The triplet states of organic molecules are normally dark. Coupling the molecules to lanthanide-doped nanocrystals makes these triplets bright, giving room-temperature phosphorescence in solution and in air, conditions under which organic phosphorescence is usually quenched.

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202621 papers
202518 papers
202421 papers
202321 papers
202223 papers
202118 papers
202015 papers
201918 papers
201813 papers
20178 papers
20167 papers
20153 papers
201411 papers
20135 papers
20125 papers
20114 papers
20102 papers
20092 papers
20082 papers