A5003839162- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Perovskite Materials and Applications
- Organic Light-Emitting Diodes Research
- Advanced Memory and Neural Computing
- Molecular Junctions and Nanostructures
- Crystallography and molecular interactions
- Thin-Film Transistor Technologies
- Fuel Cells and Related Materials
- Quantum Dots Synthesis And Properties
- Advanced Thermoelectric Materials and Devices
- Photochromic and Fluorescence Chemistry
- Advanced Chemical Physics Studies
- Analytical Chemistry and Sensors
- Spectroscopy and Quantum Chemical Studies
- Force Microscopy Techniques and Applications
- Luminescence and Fluorescent Materials
- Advanced Sensor and Energy Harvesting Materials
- Semiconductor materials and devices
- Photoreceptor and optogenetics research
- Advanced Fluorescence Microscopy Techniques
- Thermal properties of materials
- Chalcogenide Semiconductor Thin Films
King Abdullah University of Science and Technology
2018-2023
University of Oxford
2023
University of Kentucky
2010-2021
Friedrich-Alexander-Universität Erlangen-Nürnberg
2011
University of Alberta
2011
We report on bulk-heterojunction (BHJ) organic photovoltaics (OPVs) based the self-assembled monolayer (SAM) 2PACz as a hole-selective interlayer functionalized directly onto indium tin oxide (ITO) anode. The is found to change work function of ITO while simultaneously affecting morphology BHJ deposited atop. Cells with PM6:N3 and ITO-2PACz anode exhibit power conversion efficiency (PCE) 16.6%, which greater than that measured for bare (6.45%) ITO/PEDOT:PSS (15.94%) devices. enhanced...
Abstract Entanglement of states is one the most surprising and counter-intuitive consequences quantum mechanics, with potent applications in cryptography computing. In organic materials, particularly significant manifestation spin-entangled triplet-pair state, which mediates spin-conserving fission spin-0 singlet exciton into two spin-1 triplet excitons. Despite long theoretical experimental exploration, nature state inter-triplet interactions have proved elusive. Here we use a range...
Abstract Conjugated polymers that support mixed (electronic and ionic) conduction are in demand for applications spanning from bioelectronics to energy harvesting storage. To design polymer conductors high‐performance electrochemical devices, relationships between the chemical structure, charge transport, morphology must be established. A series bearing same p‐type conjugated backbone with increasing percentage of hydrophilic, ethylene glycol side chains is synthesized, their performance...
Novel p-type semiconducting polymers that can facilitate ion penetration, and operate in accumulation mode are much desired bioelectronics. Glycol side chains have proven to be an efficient method increase bulk electrochemical doping optimize aqueous swelling. One early polymer which exemplifies these design approaches was p(g2T-TT), employing a bithiophene-co-thienothiophene backbone with glycol the 3,3′ positions of bithiophene repeat unit. In this paper, analogous regioisomeric polymer,...
We have prepared, characterized and surveyed device performance for a series of electron deficient pentacenes use as acceptors in polymer bulk heterojunction solar cells, using P3HT the donor material. All materials reported here behaved acceptors, variations position nature electron-withdrawing group on pentacene core allowed tuning open-circuit voltage. Photocurrent was strongly correlated with crystal packing motif; 2D π-stacking interactions performed poorly compared exhibiting 1D...
Replacing the alkyl side chains on conventional semiconducting polymers with ethylene glycol (EG)-based is a successful strategy in molecular design of mixed conduction materials for bioelectronic devices, including organic electrochemical transistors (OECTs). Such have demonstrated capability to conduct both ionic and electronic charges can offer superior performance compared most commonly used active material, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). While many research...
Abstract Conjugated polymers with mixed ionic and electronic transport are essential for developing the complexity function of electrochemical devices. Current n‐type materials have a narrow scope low performance compared their p‐type counterparts, requiring new molecular design strategies. This work presents two naphthalene diimide‐bithiophene (NDI‐T2) copolymers functionalized hybrid alkyl‐glycol side chains, where diimide unit is segregated from ethylene glycol (EG) units within chain by...
Conjugated polymers with glycol-based chains, are emerging as a material class promising applications organic mixed ionic-electronic conductors, particularly in bioelectronics and thermoelectrics. However, little is still known about their microstructure the role of side chains determining intermolecular interactions polymer packing. Here, we use combination electrospray deposition scanning tunneling microscopy to determine prototypical glycolated conjugated (pgBTTT p(g2T-TT)) submonomer...
Significance The operation of organic field-effect transistors is governed by the processes taking place at device interfaces. mismatch in coefficients thermal expansion consecutive layers can induce inhomogeneous strain semiconductor layer and reduce performance increasing electronic trap density. We show that a high-quality necessary, but not sufficient, to obtain efficient charge-carrier transport, we propose design strategy allows us achieve intrinsic limits given regardless relative...
Charge transport layers strongly influence the performance of perovskite solar cells (PSCs). To date, compact and mesoporous scaffolds titanium dioxide have emerged as good electron (ETL), enabling record power conversion efficiencies (PCE). However, these ETLs require sintering above 400 °C, which excludes them from low-temperature applications such flexible devices silicon-heterojunction tandems. Furthermore, instability TiO2 under prolonged exposure to sunlight appears be a critical...
Electron-transporting (n-type) conjugated polymers have recently been applied in numerous electrochemical applications, where both ion and electron transport are required. Despite continuous efforts to improve their performance stability, n-type with mixed conduction still lag behind hole-transporting (p-type) counterparts, limiting the functions of devices. In this work, we investigate effect enhanced backbone coplanarity on activity ionic-electronic properties during operation aqueous...
Three lactone-based rigid semiconducting polymers were designed to overcome major limitations in the development of n-type organic thermoelectrics, namely electrical conductivity and air stability. Experimental theoretical investigations demonstrated that increasing lactone group density by benzene content from 0 % (P-0), 50 (P-50), 75 (P-75) resulted progressively larger electron affinities (up 4.37 eV), suggesting a more favorable doping process, when employing (N-DMBI) as dopant. Larger...
Exchanging hydrophobic alkyl-based side chains to hydrophilic glycol-based is a widely adopted method for improving mixed-transport device performance, despite the impact on solid-state packing and polymer-electrolyte interactions being poorly understood. Presented here molecular dynamics (MD) force field modeling alkoxylated glycolated polythiophenes. The validated against known motifs their monomer crystals. MD simulations, coupled with X-ray diffraction (XRD), show that polythiophenes...
Anthradithiophene chromophores are found in many current high‐performance organic semiconductors, even though these materials typically synthesized as an inseparable mixture of syn and anti isomers. Recent syntheses pure anthradithiophenes have shown no improvement performance for the more homogeneous system, but similar studies on isomer not been reported. In this work, a simple protocol is described to prepare fluorinated, functionalized anthradithiophenes, perform detailed analysis...
Organic field-effect transistor (OFET) performance is dictated by its composition and geometry, as well the quality of organic semiconductor (OSC) film, which strongly depends on purity microstructure. When present, impurities defects give rise to trap states in bandgap OSC, lowering device performance. Here, 2,8-difluoro-5,11-bis(triethylsilylethynyl)-anthradithiophene used a model system study mechanism responsible for degradation OFETs due isomer coexistence. The density trapping...
N-type semiconducting polymers have been recently utilized in thermoelectric devices, however they typically exhibited low electrical conductivities and poor device stability, contrast to p-type semiconductors, which much higher performing.
Abstract The organic photodiode (OPD) is a promising building block for solution‐processable, flexible, lightweight, and miniaturized photodetectors, ideal wearable applications. Despite the advances in materials used OPDs, their photocurrent light responsivity are limited, alternative methods required to boost signal response. Herein, electrochemical transistor (OECT) integrated with an OPD module unlock potential of OPDs acquire physiological signals. In this photodetector (IPD) system,...
OECTs capable of undergoing a reversible modulation ON current by up to 30% via irradiation with UV and visible light were realised blending mixed ionic–electronic polymer (pgBTTT) photoswitching spiropyran derivative (OEG-SP).
Synthetic efforts have delivered a library of organic mixed ionic-electronic conductors (OMIECs) with high performance in electrochemical transistors. The most promising materials are redox-active conjugated polymers hydrophilic side chains that reach transconductances aqueous electrolytes due to volumetric charging. Current approaches improve transconductance and device stability focus mostly on chemistry including backbone chain design. However, other parameters such as the initial...
Quantitative singlet fission has been observed for a variety of acene derivatives such as tetracene and pentacene, efforts to extend the library compounds is current interest. Preliminary calculations suggest anthradithiophenes exhibit significant exothermicity between first optically-allowed state, S1, 2 × T1 with an energy difference >5000 cm-1. Given fulfillment this ingredient fission, here we investigate capability difluorinated anthradithiophene dimer (2ADT) covalently linked by...
Semiconducting conjugated polymers bearing glycol side chains can simultaneously transport both electronic and ionic charges with high charge mobilities, making them ideal electrode materials for a range of bioelectronic devices. However, heavily glycolated polymer films have been observed to swell irreversibly when subjected an electrochemical bias in aqueous electrolyte. The excessive swelling lead the degradation their microstructure, subsequently reduced device performance. An effective...
The synthesis of three heptacyclic heteroacenes is described, namely anthra[2,3-b:7,6-b′]bis[1]benzothiophenes (ABBTs). A stepwise sequence aldol reactions provides regiochemical control, affording only the syn-isomer. ABBTs are characterized by X-ray crystallography, UV–vis absorption, and emission spectroscopy, as well cyclic voltammetry. Field effect transistors based on solution-cast thin films ABBT derivatives exhibit charge-carrier mobilities high 0.013 cm2/(V s).
The synthesis of a new benzocyclobutene based polymer, PSBBB, designed as dielectric material for use in organic thin film transistors was reported. Compared to conventional benzocyclobutene-based materials, the introduction butoxide substituent at 7-position pendant unit on polymer allowed PSBBB be cross-linked temperatures 120 °C, thus rendering it compatible with processing requirements flexible plastic substrates. cross-linking behavior investigated by Fourier transform infrared...
We present a cross-linkable wide bandgap host based on 9-(4-(10-phenylanthracene-9-yl)phenyl)-9<italic>H</italic>-carbazole.
Abstract Power conversion efficiencies of perovskite solar cells (PSCs) have rapidly increased from 3.8% to a certified 25.2% within only decade. Eliminating possible recombination losses at the interfaces is essential further improve both efficiency and stability this class emerging photovoltaic technology. Herein, simple approach for improving electron extraction PC 60 BM transport layer (ETL) presented by sequentially depositing Al:ZnO (AZO) triphenyl‐phosphine oxide (TPPO) on top it, in...