A5025604593- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- TiO2 Photocatalysis and Solar Cells
- Advanced Photocatalysis Techniques
- Perovskite Materials and Applications
- ZnO doping and properties
- Gas Sensing Nanomaterials and Sensors
- Copper-based nanomaterials and applications
- Transition Metal Oxide Nanomaterials
- Organic Light-Emitting Diodes Research
- Thin-Film Transistor Technologies
- Iron oxide chemistry and applications
- Luminescence and Fluorescent Materials
- Solar-Powered Water Purification Methods
- Catalytic Processes in Materials Science
- Graphene research and applications
- Electronic and Structural Properties of Oxides
- Photochemistry and Electron Transfer Studies
- Chalcogenide Semiconductor Thin Films
- Semiconductor materials and interfaces
- Electrodeposition and Electroless Coatings
- Nanoparticles: synthesis and applications
- Electrohydrodynamics and Fluid Dynamics
- Advanced Nanomaterials in Catalysis
- Metal and Thin Film Mechanics
Universiti Brunei Darussalam
2016-2023
Imperial College London
2010-2014
The photostability of two donor polymers, DPP-TT-T and PTB7, is compared in neat films blend with PC71BM. In both films, PTB7 shown to be relatively unstable. This observation correlate transient optical studies long lived polymer triplets molecular probe singlet oxygen yields.
Thieno[3,4 b]thiophene-alt-benzodithiophene (PTB7) is a promising donor–acceptor copolymer that has achieved high efficiencies (7–9%) in organic solar cells but suffers from poor stability and degrades when exposed to light oxygen. Using resonant Raman spectroscopy examine the nature of this photo-oxidation, three main changes vibrations conjugated backbone are observed: (1) shift benzodithiophene (BDT) CC stretch peak at ∼1489 cm−1 up ∼1499 cm−1; (2) increase relative intensity coupled...
Abstract The synthesis and characterization four diketopyrrolopyrrole containing conjugated polymers for use in organic photovoltaics is presented. Excellent energy level control demonstrated through heteroatomic substitution whilst maintaining similar solid state properties as shown by X‐ray diffraction atomic force microscopy. Inverted solar cells were fabricated with the best devices having short circuit currents exceeding 16 mA cm −2 efficiencies of over 5% irrespective whether...
This paper is concerned with the photophysics of triplet excitons in conjugated donor polymers, and their quenching by molecular oxygen. These are assayed transient absorption spectroscopy, correlated X‐ray diffraction measurements relative material crystallinity. Eleven different polymers considered, including representatives from several classes recently developed for organic solar cell applications. Triplet lifetimes an inert (nitrogen) environment range <100 ns to 5 μs. A remarkably...
We present the synthesis and characterization of two novel thiazole-containing conjugated polymers (PTTTz PTTz) that are isostructural to poly(3-hexylthiophene) (P3HT). The materials demonstrate optical morphological properties almost identical those P3HT but with HOMO LUMO levels up 0.45 eV deeper. An intramolecular planarizing nitrogen–sulfur nonbonding interaction is observed, its magnitude origin discussed. Both significantly greater open circuit voltages than in bulk heterojunction...
Charge Photogeneration: The correlation between the efficiency of photogeneration dissociated polarons and photocurrent densities for organic solar cells based on polymer:fullerene blend films is investigated. Optical assays polaron yield measured in without electrodes show a remarkably clear with short circuit density quantum complete devices. For studied herein, primary determinant generation dissociation photogenerated charges away from polymer/fullerene interface loss pathway geminate...
A new tetradodecyl-substituted DTBTBT donor unit is synthesized by a specific bis-annulation via Suzuki–Miyaura coupling and successfully incorporated into light absorbing electron copolymers for OPV hole transport OFET polymer devices. All (DTBTBT-co-benzothiadiazole (Bz), DTBTBT-co-thiophene (T) DTBTBT-co-thienothiophene (TT)) show fully coplanar backbones strong intermolecular interactions. The DTBTBT-Bz copolymer led to deep HOMO level (−5.2 eV) thus large Voc value of 0.92 V with PC71BM...
In this paper, we compare the photophysics and photovoltaic device performance of two indenofluorene based polymers: poly[2,8-(6,6,12,12-tetraoctylindenofluorene)-co-4,7-(2,1,3-benzothiodiazole] (IF8BT) poly[2,8-(6,6,12,12-tetraoctylindenofluorene)-co-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiodiazole] (IF8TBTT) blended with [6,6]-phenyl C61 butyric acid methyl ester (PCBM). Photovoltaic devices made IF8TBTT exhibit greatly superior photocurrent generation efficiency compared to those IF8BT....
The interaction between rhodamine B (RhB) and varying concentrations of graphene in aqueous dispersion was studied with spectroscopic techniques. Absorbance measurements indicate the formation an RhB–graphene complex association constant 21.02 ml/mg. Fluorescence quenching studies reveal that is a good quencher RhB emission RhB-graphene non-emissive nature, leading to apparent efficiency 94%. However, after correction for inner filter effects significant decrease absorbance due formation,...
The performance of bulk heterojunction solar cells based on a novel donor polymer DPP-TT-T was optimised by tuning molecular weight and thermal annealing.
A straightforward electrochemical dissolution-precipitation approach has been developed to synthesize nanostructured β-Ni(OH)2 powders (particle size 10-100 nm, specific surface area ∼100 m(2) g(-1)) from Ni metal anodes. The differs existing synthesis methods in that it predominantly results bulk precipitation of nanoparticles, without significant film growth on either the electrodes. Heat treatment as-synthesized afforded NiO with mostly preserved nanostructure and very high (≤100 g(-1),...
Three-dimensional (3D) porous absorbents have attracted significant attention in the oily wastewater treatment technology due to their high porosity and elasticity. Given amphiphilic surface, they a propensity simultaneously absorb water oil, which restricts range of applications. In this study, reduced graphene oxide titanium dioxide nanocomposite (rGO/TiO2) was used fabricate an ultrahydrophobic melamine sponge (MS) through interfacial modification using solution immersion technique. To...
Triclinic FeVO4 is a potential photoanode material for photoelectrochemical (PEC) water oxidation owing to its near-optimum band gap and ease of preparation from abundant elements. However, useful performance yet be achieved, apparently due the short hole diffusion length (Lp), positive flat-band (Efb), high donor density (ND). Other factors, such as transfer surface recombination kinetics, have not been studied in detail. Here, we report pure Mo-doped photoanodes prepared by simple...
In this study, Schiff bases containing salicylaldehyde moiety (namely 2-methyl-3-thiosemicarbazone and triazole) were synthesized using the conventional refluxing method. The utilized in encapsulation of ZnS nanoparticles co-precipitation characterized FTIR, UV-visible absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis. diffraction analyses suggest that base encapsulated particles form cubic crystal phase ZnS, with average crystallite sizes being...
Several earth-abundant transition-metal oxides (e.g. Fe 2 O 3 , CoO, and Cu O) possessing suitable band gaps for solar water splitting exist, but energy level alignment is often sub-optimal, i.e. the conduction valence bands do not straddle oxidation reduction potentials. Here, using a nanocrystalline-TiO -based photoelectrochemical cell as model system, we investigate effect of tuning semiconductor levels by adding Li + ions to electrolyte. The LiClO 4 addition on edges, interfacial...