A5002670481- Advanced Sensor and Energy Harvesting Materials
- Conducting polymers and applications
- Organic Electronics and Photovoltaics
- Luminescence and Fluorescent Materials
- Molecular Junctions and Nanostructures
- Supercapacitor Materials and Fabrication
- Tactile and Sensory Interactions
- Advanced Fluorescence Microscopy Techniques
- Organic Light-Emitting Diodes Research
- Nanofabrication and Lithography Techniques
- Photochromic and Fluorescence Chemistry
- Perovskite Materials and Applications
- Photonic and Optical Devices
- Near-Field Optical Microscopy
- Non-Invasive Vital Sign Monitoring
- Nonlinear Optical Materials Studies
- Synthesis and Properties of Aromatic Compounds
- Crystallization and Solubility Studies
- Thermal Radiation and Cooling Technologies
- Analytical Chemistry and Sensors
- Quantum Dots Synthesis And Properties
- Gaze Tracking and Assistive Technology
- X-ray Diffraction in Crystallography
- Advanced Biosensing Techniques and Applications
- solar cell performance optimization
University of Massachusetts Amherst
2016-2025
Physical Sciences (United States)
2024
Amherst College
2017-2019
University of Wisconsin–Madison
2013-2017
Madison Group (United States)
2017
Massachusetts Institute of Technology
2007-2013
Institute for Soldier Nanotechnologies
2008
Violet electroluminescence is rare in both inorganic and organic light-emitting diodes (LEDs). Low-cost room-temperature solution-processed lead halide perovskites with high-efficiency color-tunable photoluminescence are promising for LEDs. Here, we report color-pure violet LEDs based on a two-dimensional perovskite material, namely, 2-phenylethylammonium (C6H5CH2CH2NH3+, PEA) bromide [(PEA)2PbBr4]. The natural quantum confinement of layered (PEA)2PbBr4 allows shorter wavelength (410 nm)...
For organic photovoltaics (OPVs) to become a viable source of renewable energy, the synthesis active-layer materials will need be scaled thousands kilograms. Additionally, ultimate cost these low enough constitute only small fraction solar cell module. In this study, we present quantitative analysis, based on published small-scale synthetic procedures, estimate costs for several promising OPV when produced in large quantities. The dollars-per-gram ($ per g) is found increase linearly with...
Nanobodies are single variable domain antibodies isolated from camelids and rapidly distinguishing themselves as ideal recognition elements in biosensors due to their comparative stability, ease of production isolation, high binding affinities. However, transducing analyte by nanobodies real time is challenging, most do not directly produce an optical or electrical signal upon target recognition. Here, we report a general strategy fabricate sensitive selective electrochemical sensors...
In the past, formation of microscale patterns in far field by light has been diffractively limited resolution to roughly half wavelength radiation used. Here, we demonstrate lines with an average width 36 nanometers (nm), about one-tenth illuminating lambda1 = 325 nm, made applying a film thermally stable photochromic molecules above photoresist. Simultaneous irradiation second wavelength, lambda2 633 renders opaque writing beam except at nodal sites, which let through spatially constrained...
A fluorescent chemosensor to detect saturated nitramine and nitrate ester explosives was devised based on a photochemical reduction reaction. 10-Methyl-9,10-dihydroacridine (AcrH2) found transfer hydride ion equivalent the high RDX PETN upon irradiation at 313 nm in degassed acetonitrile solutions. Mechanistic photophysical studies indicate that photoreduction of proceeds via two-step electron−hydrogen atom reaction, whereas three-step electron−proton−electron sequence. zinc analogue...
We describe a process to transform commercial textiles and threads into electric heaters that can be cut/sewn or woven fashion lightweight fabric for local climate control personal thermal management. Off-the-shelf fabrics are coated with 1.5 μm thick film of conducting polymer, poly(3,4-ethylenedioxythiophene), using an improved reactive vapor deposition method. Changes in the hand feel, weight, breathability after coating imperceptible. The resulting electrodes possess competitively low...
Traditional textile materials can be transformed into functional electronic components upon being dyed or coated with films of intrinsically conducting polymers, such as poly(aniline), poly(pyrrole) and poly(3,4-ethylenedioxythiophene). A variety devices are built from the conductive fibers fabrics thus obtained, including: physiochemical sensors, thermoelectric fibers/fabrics, heated garments, artificial muscles supercapacitors. In all these cases, electrical performance device ruggedness...
Three-dimensional (3D) nanowire (NW) architectures are considered as superior electrode design for photovoltaic devices compared to NWs or nanoparticle systems in terms of improved large surface area and charge transport properties. In this paper, we report development lead iodide perovskite solar cells based on a novel 3D TiO2 NW architectures. The nanostructure was synthesized via surface-reaction-limited pulsed chemical vapor deposition (SPCVD) technique that also implemented the...
The motivation of this study is to determine if small amounts designer additives placed at the polymer-fullerene interface in bulk heterojunction (BHJ) solar cells can influence their performance. A series AB-alternating side-chain-functionalized poly(thiophene) analogues, P1-6, are designed selectively localize between regioregular poly(3-hexylthiophene) (rr-P3HT) and PC(n)BM (n = 61, 71). side chains every other repeat unit P1-6 contain various terminal aromatic moieties. BHJ containing...
Abstract Wearable thermoelectric generators are a promising energy source for powering activity trackers and portable health monitors. However, known iterations of wearable have large form factors, contain expensive or toxic materials with low elemental abundance, quickly reach thermal equilibrium human body, meaning that power can only be generated over short period wear. Here, an all‐fabric thermopile is created by vapor printing persistently p ‐doped poly(3,4‐ethylenedioxythiophene)...
We investigate the bias-stress effect in field-effect transistors (FETs) consisting of 1,2-ethanedithiol-treated PbS quantum dot (QD) films as charge transport layers a top-gated configuration. The FETs exhibit ambipolar operation with typical mobilities on order μe = 8 × 10–3 cm2 V–1 s–1 n-channel and μh 1 p-channel operation. When FET is turned or mode, established drain–source current rapidly decreases from its initial magnitude stretched exponential decay, manifesting effect. choice...
Fabrics are pliable, breathable, lightweight, ambient stable, and have unmatched haptic perception. Here, a vapor deposition method is used to transform off‐the‐shelf plain‐woven fabrics, such as linen, silk, bast fiber into metal‐free conducting electrodes. These fabric electrodes resistant wear, stable after laundering ironing, can be body‐mounted with little detriment their performance. A unique by‐product of conformally coating fabrics that textile parameters, thread material porosity,...
Vapor printing electrodes on seedlings allows on-demand health monitoring of growing plants using bioimpedance spectroscopy.
All‐textile triboelectric generators (TEGs) allow for seamless integration of TEGs into garments, while maintaining the intrinsic flexibility, breathability, durability, and aesthetic value normal textiles. However, practical approaches to construct fabric using traditional textile processes, such as sewing, weaving, knitting, are underreported. In this work, two create an all‐textile TEG straight‐forward manufacturing methods presented. The first approach is assemble different cloths...
Abstract The ability of conjugated polymers to function as electronic materials is dependent on the efficient transport excitons along polymer chain. Generally, photophysics chromophore monomer dictate excited state behavior corresponding polymers. Different molecular structures are examined study role lifetimes and conformations energy transfer. incorporation rigid, three‐dimensional scaffolds, such iptycenes cyclophanes, can encourage an oblique packing units a polymer, thus allowing...
A thin-film transistor: An n-type polymer semiconductor, poly(2,3-bis(perfluorohexyl)thieno[3,4-b]pyrazine), was synthesized through a Pd-catalyzed polycondensation employing perfluorinated multiphase solvent system. This is the first example of an semiconductor with exclusive solubility in fluorinated solvents. The fabrication organic field effect transistors containing this new shown.
Abstract Conventional vision-based systems, such as cameras, have demonstrated their enormous versatility in sensing human activities and developing interactive environments. However, these systems long been criticized for incurring privacy, power, latency issues due to underlying structure of pixel-wise analog signal acquisition, computation, communication. In this research, we overcome limitations by introducing in-sensor computation through the distribution interconnected photodetectors...
The nitramine-containing explosive RDX and the nitroester-containing PETN are shown to be susceptible photofragmentation upon exposure sunlight. Model compounds containing nitroester nitramine moieties also fragment UV irradiation. products of this reactive, electrophilic NO(x) species, such as nitrous nitric acid, oxide, nitrogen dioxide. N,N-Dimethylaniline is capable being nitrated by PETN. A series 9,9-disubstituted 9,10-dihydroacridines (DHAs) synthesized from either N-phenylanthranilic...
Wearable electrochemical sensors have the potential to overcome problem of infrequent clinical visits that leads transient events diagnostic importance being unduly overlooked. The promise real-time, personalized health care has driven multidisciplinary work on fabricating various forms wearable sensors. Although remarkable advances in device form factor and integrated circuit design been achieved, notable hurdles, such as shelf life, reuseability, flex sweat resistance, longitudinal...
Vapor-deposited polymer tattoos enable on-site monitoring of ozone-induced oxidative damage in fruiting plants.
A series of 6,6-dicyanofulvene derivatives are synthesized starting from masked, dimeric, or monomeric cyclopentadienones. The reactivities 6,6-dicyanofulvenes relative to their parent cyclopentadienones discussed. 6,6-Dicyanofulvenes capable undergoing two consecutive, reversible, one-electron reductions and presented as potential n-type small molecules.