A5075515123- Organic Light-Emitting Diodes Research
- Organic Electronics and Photovoltaics
- Luminescence and Fluorescent Materials
- Conducting polymers and applications
- Photochemistry and Electron Transfer Studies
- X-ray Diffraction in Crystallography
- Catalytic Cross-Coupling Reactions
- Thin-Film Transistor Technologies
- Crystallization and Solubility Studies
- Semiconductor Lasers and Optical Devices
- Organic and Molecular Conductors Research
- Cassava research and cyanide
- Weed Control and Herbicide Applications
- Porphyrin and Phthalocyanine Chemistry
- Random lasers and scattering media
- Photonic and Optical Devices
- Chalcogenide Semiconductor Thin Films
- Perovskite Materials and Applications
- Nanomaterials and Printing Technologies
- Strong Light-Matter Interactions
- Laser Design and Applications
- Photonic Crystals and Applications
- Nonlinear Optical Materials Studies
- Nanocluster Synthesis and Applications
- Catalytic Alkyne Reactions
The University of Queensland
2019-2024
Applied Photonics (United Kingdom)
2022
Brisbane School of Theology
2020
Abstract Polaron-induced exciton quenching in thermally activated delayed fluorescence (TADF)-based organic light-emitting diodes (OLEDs) can lead to external quantum efficiency (EQE) roll-off and device degradation. In this study, singlet-polaron annihilation (SPA) triplet-polaron (TPA) were investigated under steady-state conditions their relative contributions EQE quantified, using experimentally obtained parameters. It is observed that both TPA SPA 2,4,5,6-tetra(9 H...
Abstract This work demonstrates successful large area inkjet printing of a thermally activated delayed fluorescence (TADF) material as the emitting layer organic light-emitting diodes (OLEDs). TADF materials enable efficient light emission without relying on heavy metals such platinum or iridium. However, low-cost manufacturing large-scale OLEDs has been restricted due to their incompatibility with solution processing techniques. In this study, we develop ink formulation for and show jet...
Abstract Recent studies have demonstrated that in thermally activated delayed fluorescence (TADF) materials, efficient reverse intersystem crossing occurs from nonradiative triplet exited states to radiative singlet excited due a small singlet–triplet energy gap. This significantly influences exciton annihilation processes and external quantum efficiency roll‐off TADF based organic light‐emitting diodes (OLEDs). In this work, comprehensive quenching model is developed for system determine...
The unique four-level photocycle characteristics of excited-state intramolecular proton transfer (ESIPT) materials enable population inversion and large spectral separation between absorption emission through their respective enol keto forms. This leads to minimal or no self-absorption losses, a favorable feature in acting as an optical gain medium. While conventional ESIPT with enol-keto tautomerism process are widely known, zwitterionic materials, particularly those high photoluminescence,...
Abstract Over the years, achieving efficient electroluminescence (EL) while simultaneously having low light amplification thresholds under optical excitation has been key to progression toward long‐thought objective of electrically pumped organic lasers. While significant progress in this regard made for semiconductors emitting blue–green region visible spectrum, laser dyes with low‐energy emission (>600 nm) still suffer from high amplified spontaneous (ASE) and external quantum...
Abstract While noteworthy progress has been made on organic solid‐state lasers with low amplified spontaneous emission (ASE) thresholds and high optical gains in blue green colors, the same advancement not achieved for red laser dyes. This is mainly due to their photoluminescence quantum yields (PLQYs) because of “energy bandgap law.” Here, a new family solution‐processable semiconductor dyes based bay‐annulated indigo derivative (Cibalackrot) deep‐red reported. They exhibit excellent PLQYs...
Abstract High mechanical flexibility and wavelength tunability of organic semiconductor materials have propelled the development lasers (OSLs) as a complementary technology to current inorganic lasers. While excellent progress has been made across multiple aspects OSLs, demonstration long‐pulse operation [quasi‐continuous wave (qCW) or continuous (CW)] lasing presented significant challenges due detrimental accumulation triplets under photoexcitation substantial quenching singlet excitons,...
Organic lasers have attracted increasing attention owing to their superior characteristics such as lightweight, low-cost manufacturing, high mechanical flexibility, and emission-wavelength tunability. Recent breakthroughs include electrically pumped organic laser diodes an driven laser, integrated with light-emitting diode pumping. However, the availability of efficient deep blue chromophores remains limited. In this study, we develop two novel rigid oligophenylenes, end-capped carbazole...
Solution-processed hyperfluorescent red organic light-emitting diodes with external quantum efficiencies of 15.3% was achieved by using cibalackrot as the fluorescent emitter, where attaching tert -butyl groups to assistant host significantly contributes device performance.
Abstract Organic semiconductor dyes have attracted high interest as laser gain media owing to their judicious features of solution processability, lightweight, mechanical flexibility, wavelength‐tunability, and low‐cost manufacture. In this work, fluorene‐carbazolylstyryl hybrids are reported, SFCz BSTFCz, new processable organic show molar extinction coefficients (up 1.98 × 10 5 dm 3 mol −1 cm ), photoluminescence quantum yields 81 ± 4%), radiative decay constants 1.24 9 s low film...
Color purity is a critical prerequisite for full color displays. Creation of deep-red phosphorescent materials with high PLQYs particularly challenging because the "energy gap law". Simultaneously achieving yielding solution processable Pt(II) complexes further complicates this challenge. In report, we developed high-yielding synthetic route to processable/deep-red complex rigid tetradentate structure, in which identified an octahedral Pt(IV) as major side product formed under standard...
Abstract External quantum efficiency (EQE) roll‐off under high current injection has been one of the major limiting factors toward development organic semiconductor laser diodes (OSLDs). While significant progress in this regard made on semiconductors (OSCs) emitting blue–green region visible spectrum, OSCs with longer wavelength emission (>600 nm) have fallen behind both material and advancement device architectures suitable for realization OSLDs. Therefore, to make simultaneous...
The effect of excited-state intramolecular proton-transfer (ESIPT) laser material rigidity on photophysical properties and amplified spontaneous emission (ASE) thresholds ( E ASEth) is studied.
Abstract Significant efforts are dedicated to developing new classes of organic semiconductor materials achieve electrically pumped lasing. However, further advancements necessary understand the relationship between structure and property for creation innovative laser with high stability, low triplet yield, ultra‐low lasing threshold, low‐efficiency roll‐off at ultra‐bright electroluminescence. Here, a design principle is validated materials, demonstrating simultaneous enhancement in key...
Weed management is an essential intervention for maintaining food security and protecting biodiversity but heavily reliant on chemical control measures (
Abstract N‐Heterocyclic carbene (NHC) cyclometalated gold(III) complexes remain very scarce and therefore their photophysical properties currently underexplored. Moreover, emitting in the blue region of electromagnetic spectrum are rare. In this work, a series four phosphorescent was investigated bearing different NHC monocyclometalated (C^C*)‐type ligands dianionic (N^N)‐type ancillary ligand ((N^N)=5,5’‐(propane‐2,2‐diyl)bis(3‐(trifluoromethyl)‐1 H ‐pyrazole) (mepzH 2 )). The exhibit...
Hyperfluorescent organic light-emitting diodes (HF-OLEDs) enable a cascading Förster resonance energy transfer (FRET) from suitable thermally activated delayed fluorescent (TADF) assistant host to end-emitter give efficient OLEDs with relatively narrowed electroluminescence compared TADF-OLEDs. Efficient HF-OLEDs require optimal FRET minimum triplet diffusion via Dexter-type (DET) the TADF end-emitter. To hinder DET, steric protection of end-emitters has been proposed disrupt transfer. In...
Abstract The field of organic photodiodes (OPDs) has witnessed continuous development in the last decade. Although a considerable portion electron‐donating materials are polymers, there been an existential gap deciphering influence polymer's molecular‐weight on photodiode performance. We take up OPDs based 5,5′‐[(9,9‐Dioctyl‐9 H ‐fluorene‐2,7‐diyl)bis(2,1,3‐benzothiadiazole‐7,4diylmethylidyne)]bis[3‐ethyl‐2‐thioxo‐4‐thiazolidinone] (FBR) acceptor material blended with three different...
Abstract White organic light-emitting diodes (WOLEDs) have several desirable features, but their commercialization is hindered by the poor stability of blue light emitters and high production costs due to complicated device structures. Herein, we investigate a standard emitting hole transporting material (HTM) N , N' -bis(naphthalen-1-yl)- -bis(phenyl)benzidine (NPB) its exciplex emission upon combining with suitable electron (ETM), 3-(biphenyl-4-yl)-5-(4- tert -butylphenyl)-4-phenyl-4 H...
A host–guest matrix enables both strong exciton-photon coupling and efficient energy transfer. This combination holds promise toward reduced laser thresholds eventual electrical injection.
Alkylated benzothienobenzothiophenes are an important class of organic semiconductors that exhibit high performance in solution-processed field-effect transistors. In this work, we study the near-edge x-ray absorption fine-structure (NEXAFS) spectra 2,7-didecyl[1]benzothieno[3,2-b][1]benzothiophene (C10-BTBT) at both carbon and sulfur K-edges. Angle-resolved experiments thin films performed to characterize dichroism associated with molecular orientation. First-principles calculations using...
The synthesis, characterization, and spectroscopic investigations of a new solution‐processable N ‐styrylcarbazole‐linked tetraphenylethylene (TPE) derivative ( TPE‐BCzS ) are reported, exhibiting green–orange emission. While the material displays weak photoluminescence (PL) in solution with low PL quantum yield (PLQY 4 ± 0.2%), significant enhancement neat‐film PLQY (55 8%) is observed. Studies using steady‐state spectroscopy, femtosecond nanosecond transient absorption spectroscopy reveal...
Abstract In this work, we describe the design and synthesis of a novel, organic emissive small donor–acceptor–donor molecule, 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-9 H -fluoren-9-one, its incorporation into functional light-emitting diode (OLED) devices. The molecule was developed through three-step procedure with high yields using low-cost commercially available materials. Photophysical analysis shows emission from both locally excited (LE) intramolecular charge transfer (ICT)...