A5028806436- 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
- Thin-Film Transistor Technologies
- Molecular Junctions and Nanostructures
- Quantum Dots Synthesis And Properties
- Advanced Memory and Neural Computing
- Organic and Molecular Conductors Research
- Nanowire Synthesis and Applications
- Advanced Sensor and Energy Harvesting Materials
- Fullerene Chemistry and Applications
- Crystallography and molecular interactions
- Nonlinear Optical Materials Studies
- Synthesis and Properties of Aromatic Compounds
- Chalcogenide Semiconductor Thin Films
- Analytical Chemistry and Sensors
- Innovative Microfluidic and Catalytic Techniques Innovation
- ZnO doping and properties
- Semiconductor Lasers and Optical Devices
- Green IT and Sustainability
- Organic Chemistry Cycloaddition Reactions
- Cyclopropane Reaction Mechanisms
McGill University
2019-2023
University of Calgary
2022-2023
King Abdullah University of Science and Technology
2013-2022
Kootenay Association for Science & Technology
2020
The organic electrochemical transistor (OECT), capable of transducing small ionic fluxes into electronic signals in an aqueous environment, is ideal device to utilize bioelectronic applications. Currently, most OECTs are fabricated with commercially available conducting poly(3,4-ethylenedioxythiophene) (PEDOT)-based suspensions and therefore operated depletion mode. Here, we present a series semiconducting polymers designed elucidate important structure–property guidelines required for...
Abstract Organic electrochemical transistors (OECTs) are receiving significant attention due to their ability efficiently transduce biological signals. A major limitation of this technology is that only p-type materials have been reported, which precludes the development complementary circuits, and limits sensor technologies. Here, we report first ever n-type OECT, with relatively balanced ambipolar charge transport characteristics based on a polymer supports both hole electron along its...
The fields of photovoltaics, photodetection and light emission have seen tremendous activity in recent years with the advent hybrid organic-inorganic perovskites. Yet, there been far fewer reports perovskite-based field-effect transistors. lateral interfacial transport requirements transistors make them particularly vulnerable to surface contamination defects rife polycrystalline films bulk single crystals. Here, we demonstrate a spatially-confined inverse temperature crystallization...
Abstract Solution-printed organic semiconductors have emerged in recent years as promising contenders for roll-to-roll manufacturing of electronic and optoelectronic circuits. The stringent performance requirements thin-film transistors (OTFTs) terms carrier mobility, switching speed, turn-on voltage uniformity over large areas require currently achieved by single-crystal devices, but these suffer from scale-up challenges. Here we present a new method based on blade coating blend conjugated...
Blade-coating has recently emerged as a scalable fabrication method for hybrid perovskite solar cells, but it currently underperforms spin-coating, yielding power conversion efficiency (PCE) of ∼15% CH3NH3PbI3 (MAPbI3). We investigate the solidification MAPbI3 films in situ during spin/blade-coating using optical and X-ray scattering methods. find that coating conditions profoundly influence crystallization process, which proceeds through intermediate crystalline solvates. The polymorphism...
A novel photoactive polymer with two different molecular weights is reported, based on a new building block: thieno[3,2-b][1]benzothiophene isoindigo. Due to the improved crystallinity, optimal blend morphology, and higher charge mobility, solar-cell devices of high-molecular-weight exhibit superior performance, affording efficiencies 9.1% without need for additives, annealing, or additional extraction layers during device fabrication.
Blending of small‐molecule organic semiconductors (OSCs) with amorphous polymers is known to yield high performance thin film transistors (OTFTs). Vertical stratification the OSC and polymer binder into well‐defined layers crucial in such systems their vertical order determines whether coating compatible a top and/or bottom gate OTFT configuration. Here, we investigate formation blends prepared via spin‐coating conditions which bilayer trilayer stratifications. We use combination situ...
Abstract Colloidal quantum dot (CQD) solar cells have risen rapidly in performance; however, their low‐cost fabrication under realistic ambient conditions remains elusive. This study uncovers that humid environments curtail the power conversion efficiency (PCE) of by preventing needed oxygen doping hole transporter during fabrication. A simple oxygen‐doping step enabling manufacturing irrespective seasonal humidity variations is devised. Solar with PCE > 10% are printed high at...
The addition of dimethylsulfoxide and Zonyl into poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) can be combined to achieve excellent electrical, optical, mechanical properties. We demonstrate that it is possible produce highly transparent conducting electrodes (FoM > 35) with low Young's modulus high carrier density. investigated the relationship between transport properties PEDOT:PSS morphology microstructure these films by performing Hall effect measurement, atomic...
Herein, we elucidate the photodegradation pathway of A-D-A-type non-fullerene acceptors for organic photovoltaics. Using IT-4F as a benchmark example, isolated photoproducts and proved them isomers formed by 6-e electrocyclic reaction between dicyanomethylene unit thiophene ring, followed 1,5-sigmatropic hydride shift. This photoisomerization was accelerated under inert conditions, explained DFT calculations predicting triplet-mediated path (quenchable oxygen). Adding controlled amounts...
Spin-coating is the most commonly used technique for lab-scale production of solution processed organic electronic, optoelectronic and photovoltaic devices. produces efficient solution-processed solar cells has been preferred approach rapid screening optimization new semiconductors formulations electronic applications, both in academia industrial research facilities. In this article we demonstrate, first time, a spin-coating experiment monitored situ by time resolved UV-visible absorption,...
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...
Scalable manufacturing of small‐molecule organic thin film transistors (OTFTs) with performance approaching single crystals requires extraordinary control over microstructures and morphologies semiconductors (OSCs). Here, contact‐induced nucleation in the context OSCs OSC:polymer blends prepared by blade coating, a printing process capable mimicking large area batch roll‐to‐roll manufacturing, is investigated. Using polarized optical microscopy, microbeam grazing incidence wide angle X‐ray...
Abstract Molecular doping is a powerful tool with the potential to resolve many of issues currently preventing organic thin‐film transistor (OTFT) commercialization. However, addition dopant molecules into semiconductors often disrupts host lattice, introducing defects and harming electrical transport. New dopant‐based systems that overcome practical utilization issues, while still reaping performance benefits, would therefore be extremely valuable. Here, impact p‐doping on charge transport...
Abstract Incorporating the molecular organic Lewis acid tris(pentafluorophenyl)borane [B(C 6 F 5 ) 3 ] into semiconductors has shown remarkable promise in recent years for controlling operating characteristics and performance of various opto/electronic devices, including, light‐emitting diodes, solar cells, thin‐film transistors (OTFTs). Despite demonstrated potential, however, to date most work been limited B(C with latter serving as prototypical air‐stable system. Herein, use...
Solution-processed metal halide perovskite (MHP) single crystals (SCs) are in high demand for a growing number of printed electronic applications due to their superior optoelectronic properties compared polycrystalline thin films. There is an urgent need make SC fabrication facile, scalable, and compatible with the manufacturing infrastructure. Here, universal cosolvent evaporation (CSE) strategy presented by which SCs arrays produced directly on substrates via printing coating methods...
Spin-coating of TIPS-pentacene is examined <italic>in situ</italic> to reveal that residual solvent can heal structural defects and dramatically increase carrier mobility.
Abstract The impact of the gate dielectric on contact resistance in organic thin‐film transistors (OTFTs) is investigated using electrical characterization, bias‐stress stability measurements, and bandgap density states (DOS) analysis. Two similar materials, namely Cytop poly[4,5‐difluoro‐2,2‐bis(trifluoromethyl)‐1,3‐dioxole‐ co ‐tetrafluoroethylene] (Teflon AF2400), are tested top‐gate bottom‐contact OTFTs. Cytop‐based OTFTs found to be greater than that AF2400‐based devices, even though...
We explore a series of furan-based non-fullerene acceptors and report their optoelectronic properties, solid-state packing, photodegradation mechanism application in photovoltaic devices. Incorporating furan building blocks leads to the expected enhanced backbone planarity, reduced band gap red-shifted absorption these acceptors. Still, position molecule is critical for stability device performance. found that originates from two distinct pathways: electrocyclic photoisomerization...
Programmable crystallization of thin films produces patterns and bespoke microstructures for semiconductor applications.
The first π-conjugated macrocyclic system with an oligofuran backbone display planar conformation and forms large π-aggregates, in contrast to the twisted of small oligothiophenes.
Abstract Solution deposition of organic optoelectronic materials enables fast roll‐to‐roll manufacturing photonic and electronic devices on any type substrate at low cost. But controlling the film microstructure when it crystallizes from solution can be challenging. This represents a major limitation this technology, since microstructure, in turn, governs charge transport properties material. Further, solvents typically used are hazardous, which precludes their incorporation large‐scale...
Blade-coating is used to fabricate high hole mobility organic transistors based on a p-doped small-molecule:polymer blend semiconductor.
Molecular doping has emerged as a powerful strategy to tune the charge transport properties of organic field-effect transistors (OFETs). However, limited tool-box molecular dopants and unresolved challenges stability, uniformity doping, matching energy levels constrain achieved OFET device performance thwart practical applications. Here, nitrofluorene (NF) acceptors are introduced effective p-dopants in polymer OFETs, resulting outstanding standard commercial...