A5027167858- Strong Light-Matter Interactions
- Thermal Radiation and Cooling Technologies
- Plasmonic and Surface Plasmon Research
- Molecular Junctions and Nanostructures
- Mechanical and Optical Resonators
- Perovskite Materials and Applications
- Quantum and electron transport phenomena
- Semiconductor Quantum Structures and Devices
- Ga2O3 and related materials
- GaN-based semiconductor devices and materials
- 2D Materials and Applications
- Quantum optics and atomic interactions
- Quantum Dots Synthesis And Properties
- Semiconductor materials and devices
- Photonic and Optical Devices
- Quantum Electrodynamics and Casimir Effect
- Thin-Film Transistor Technologies
- Metabolomics and Mass Spectrometry Studies
- Impact of Technology on Adolescents
- Nanowire Synthesis and Applications
- Advanced Fluorescence Microscopy Techniques
- Chalcogenide Semiconductor Thin Films
- Acoustic Wave Resonator Technologies
- Solid-state spectroscopy and crystallography
- Near-Field Optical Microscopy
University of Sheffield
2018-2025
University of Cambridge
2021
University of Cyprus
2021
Cornell University
2021
Hangzhou Normal University
2021
Nanjing University
2021
Sheffield City Council
2019
University of Crete
2014-2019
FORTH Institute of Electronic Structure and Laser
2014-2017
Abstract While there have been numerous reports of long‐range polariton transport at room‐temperature in organic cavities, the spatiotemporal evolution propagation is scarcely reported, particularly initial coherent sub‐ps regime, where photon and exciton wavefunctions are inextricably mixed. Hence detailed process exciton‐polariton and, particular, role dark states has remained poorly understood. Here, femtosecond transient absorption microscopy used to directly image motion microcavities...
Exciton-polaritons are quasiparticles with mixed photon and exciton character that demonstrate rich quantum phenomena, novel optoelectronic devices the potential to modify chemical properties of materials. Organic materials current interest as active for their ability sustain exciton-polaritons even at room temperature. However, within organic devices, it is often 'dark' spin-1 triplet excitons dominate operation. These triplets have been largely ignored in treatments polaritons, which...
Non-radiative energy transfer between spatially-separated molecules in a microcavity can occur when an excitonic state on both are strongly-coupled to the same optical mode, forming so-called "hybrid" polaritons. Such has previously been explored thin-films of different relatively closely spaced (≈100 nm). In this manuscript, we explore strong-coupled microcavities which two J-aggregated molecular dyes were separated by spacer layer having thickness up 2 μm. Here, strong light-matter...
The development of scalable deposition methods for perovskite solar cell materials is critical to enable the commercialization this nascent technology. Herein, we investigate use and processing nanoparticle SnO2 films as electron transport layers in cells develop ultrasonic spray coating slot-die coating, leading photovoltaic device efficiencies over 19%. effects postprocessing treatments (thermal annealing, UV ozone, O2 plasma) are then probed using structural spectroscopic techniques...
Strong-coupling between excitons and confined photonic modes can lead to the formation of new quasi-particles termed exciton-polaritons which display a range interesting properties such as super-fluidity, ultrafast transport Bose-Einstein condensation. typically occurs when an excitonic material is confided in dielectric or plasmonic microcavity. Here, we show polaritons form at room temperature chemically diverse, organic semiconductor thin films, despite absence external cavity. We find...
Nonlinear interactions between excitons strongly coupled to light are key for accessing quantum many-body phenomena in polariton systems. Atomically-thin two-dimensional semiconductors provide an attractive platform strong light-matter coupling owing many controllable excitonic degrees of freedom. Among these, the recently emerged exciton hybridization opens access unexplored species, with a promise enhanced interactions. Here, we employ hybridized interlayer (hIX) bilayer MoS2 achieve...
The addition of alkali metal halides to hybrid perovskite materials can significantly impact their crystallisation and hence performance when used in solar cell devices. Previous work on the use potassium iodide (KI) active layers passivate defects triple-cation mixed-halide perovskites has been shown enhance luminescence efficiency reduce current-voltage hysteresis. However, operational stability KI passivated cells under ambient conditions remains largely unexplored. By investigating with...
Strong light-matter coupling to form exciton- and vibropolaritons is increasingly touted as a powerful tool alter the fundamental properties of organic materials. It proposed that these states their facile tunability can be used rewrite molecular potential energy landscapes redirect photophysical pathways, with applications from catalysis electronic devices. Crucial exchange between coherent, bright polaritons incoherent dark states. One most potent tools explore this interplay transient...
Polaritons are quasi-particles composed of a superposition excitons and photons that can be created within strongly coupled optical microcavity. Here, we describe structure in which microcavity containing an organic semiconductor is to second series weakly inorganic quantum wells. We show hybridisation occurs between the modes two cavities, creating delocalised polaritonic state. By electrically injecting electron-hole pairs into quantum-well system, able transfer energy cavities populate...
Exciton-polaritons in 2D lattice geometries now attract considerable attention as systems which to explore new physics. However, such structures are relatively difficult fabricate this can involve sophisticated milling or etching of cavity layers create arrays defects. Here, a straightforward technique is reported that allows rapid fabrication polariton lattices operate at room temperature. Specifically, laser patterning has been used write square defects into sacrificial polymer layer. An...
<title>Abstract</title> Ultrafast all-optical logic devices based on nonlinear light-matter interactions hold the promise to overcome speed limitations of conventional electronic devices. Strong coupling excitons and photons inside an optical resonator enhances such generates new polariton states which give access unique phenomena, as Bose-Einstein condensation, used for ultrafast transistors. However, reach threshold condensation high quality factors pulse energies are required. Here we...
Abstract Polariton lasers are coherent light sources based on the condensation of exciton-polaritons in semiconductor microcavities, which occurs either kinetic or thermodynamic (Bose-Einstein) regime. Besides their fundamental interest, polariton have potential extremely low operating thresholds. Here, we demonstrate ultra-low threshold lasing at room temperature, using an all-dielectric, GaN membrane-based microcavity, with a spontaneously-formed zero-dimensional trap. The microcavity is...
Abstract Non‐radiative energy transfer between spatially‐separated molecules in a microcavity can occur when an excitonic state on both are strongly‐coupled to the same optical mode, forming so‐called “hybrid” polaritons. Such has previously been explored thin‐films of different relatively closely spaced (≈100 nm). In this manuscript, we explore strong‐coupled microcavities which two J‐aggregated molecular dyes were separated by spacer layer having thickness up 2 μm. Here, strong...
We have developed a simplified approach to fabricate high-reflectivity mirrors suitable for applications in strongly-coupled organic-semiconductor microcavity. Such are based on small number of quarter-wave dielectric pairs deposited top thick silver film that combine high reflectivity and broad bandwidth. Using this approach, we construct microcavity containing the molecular dye BODIPY-Br which bottom cavity mirror is composed layer coated by SiO2 Nb2O5 film, show undergoes polariton...
We have fabricated organic semiconductor microcavities having an extended optical path-length (up to 2 µm) that contain J-aggregates of a cyanine dye. These structures are studied using optical-reflectivity and found be characterized by series polaritonic modes. By changing the effective oscillator strength dye within cavity, we evidence transition from “normal” strong coupling in which photon modes coupled one another via excitonic molecular state photon-modes become decoupled. use...
We have fabricated organic polariton microcavities that exhibit remarkable photostability, even in the condensation regime.
Abstract The manipulation of exciton–polaritons and their condensates is great interest due to applications in polariton simulators high‐speed, all‐optical logic devices. Until now, methods trapping manipulating such are not dynamically reconfigurable or resulted an undesirable reduction the exciton–photon coupling strength. Here, a new strategy for ultrafast control resonances via transient modification optical cavity mode presented. Multilayer organic semiconductor microcavities that...
We demonstrate a new all-optical method to measure absorption coefficients in any family of as-grown nanowires, provided they are grown on substrate having considerable difference permittivity with the nanowire-air matrix. In case high crystal quality, strain-free GaN Si (111) substrates, extracted do not exhibit enhancement compared bulk values, unlike relevant claims literature. This could be attributed relatively small diameters, short heights, and densities our nanowire arrays.
Strong coupling to the electronic or vibronic transitions of an organic semiconductor has been extensively studied in microcavity structures which a molecular film is placed between two closely spaced mirrors. Recent experiments suggest that such strong can be used modify chemical reactions; however, geometry conventional makes studies difficult as they limit ability molecules interact with their local environment. Here, we show optical achieved even when are located on surface dielectric...
Abstract Two-dimensional semiconducting transition metal dichalcogenides embedded in optical microcavities the strong exciton-photon coupling regime may lead to promising applications spin and valley addressable polaritonic logic gates circuits. One significant obstacle for their realization is inherent lack of scalability associated with mechanical exfoliation commonly used fabrication two-dimensional materials heterostructures. Chemical vapor deposition offers an alternative scalable...
We have fabricated an open-cavity microcavity structure containing a thin film of the biologically-derived molecule β-carotene. show that β-carotene absorption can be described in terms series Lorentzian functions approximate 0-0, 0-1, 0-2, 0-3 and 0-4 electronic vibronic transitions. On placing this molecular material into microcavity, we obtain anti-crossing between cavity mode 0-1 transition, however other transitions remain intermediate or weak-coupling regime due to their lower...
We explore the generation of anti-Stokes fluorescence from strongly coupled organic dye microcavities following resonant ground-state excitation. observe polariton emission along lower branch, with our results indicating that this process involves a return to exciton reservoir and absorption thermal energy molecules in vibrationally excited ground-state. speculate population "hot" polaritons is enhanced by fact cavity suppresses Stokes-shifted fluorescence, as it energetically located below...
Abstract Exciton-polaritons (EPs) are quasiparticles formed by the hybridization of excitons with light modes. As organic semiconductors sustain stable at room-temperature, these materials being actively studied for room temperature polaritonic devices 1–3 . This is typically in form cavity-based systems, where molecules confined between metallic or dielectric mirrors 4–6 a plasmonic gap 7,8 In such systems strong light-matter coupling gives rise to polariton splittings on order 200 300 meV...
Strong coupling of a confined optical field to the excitonic or vibronic transitions molecular material results in formation new hybrid states called polaritons. Such effects have been extensively studied Fabry-Pèrot microcavity structures where an organic is placed between two highly reflective mirrors. Recently, theoretical and experimental evidence has suggested that strong can be used modify chemical reactivity as well photophysical functionalities. However, geometry conventional limits...