We describe herein the construction of a simple, low-power, broadly responsive vapor sensor. Carbon black−organic polymer composites have been shown to swell reversibly upon exposure vapors. Thin films carbon were deposited across two metallic leads, and swelling-induced resistance changes signaled presence To identify classify vapors, arrays such vapor-sensing elements constructed, with each element containing same black conducting phase but different organic as insulating phase. The...

Herein we report the synthesis and characterization of a series 6,12-diarylindeno[1,2-b]fluorenes (IFs). Functionalization with electron donor acceptor groups influences ability IF scaffold to undergo two-electron oxidation reduction yield corresponding 18- 22-π-electron species, respectively. A single crystal pentafluorophenyl-substituted can serve as an active layer in organic field-effect transistor (OFET). The important finding is that single-crystal OFET yields ambipolar device able...

Acceptance is good! 2,8-Disubstituted indeno[1,2-b]fluorenes (see structure; TIPS=triisopropylsilyl) were synthesized and characterized. Electrochemical, optical, computational data indicate that these electron-accepting hydrocarbons possess low-lying HOMO LUMO energies, gap energies are comparable to common organic n-type semiconducting materials.

We have synthesized a series of aza[8]cycloparaphenylenes containing one, two, and three nitrogens to probe the impact nitrogen doping on optoelectronic properties solid state packing. Alkylation these azananohoops afforded first donor–acceptor nanohoops where phenylene backbone acts as donor pyridinium units act acceptor. The was then studied experimentally computationally provide new insight into effect functionalization properties.

ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTPotentially Confusing: Potentials in ElectrochemistryShannon W. Boettcher*Shannon BoettcherThe Department of Chemistry and Biochemistry the Oregon Center for Electrochemistry, University Oregon, Eugene, 97403, United StatesCenter Interfacial Ionics, States*[email protected]More by Shannon Boettcherhttp://orcid.org/0000-0001-8971-9123, Sebastian Z. OenerSebastian OenerDepartment Interface Science, Fritz-Haber Institute Max Planck Society, Berlin,...

Organometal halide perovskite semiconductors have emerged as promising candidates for optoelectronic applications because of the outstanding charge carrier transport properties, achieved with low-temperature synthesis. Here, we present highly sensitive sub-bandgap external quantum efficiency (EQE) measurements Au/spiro-OMeTAD/CH3NH3Pb(I1–xBrx)3/TiO2/FTO/glass photovoltaic devices. The room-temperature spectra show exponential band tails a sharp onset characterized by low Urbach energies (Eu)...

A statistical metric, based on the magnitude and standard deviations along linear projections of clustered array response data, was utilized to facilitate an evaluation performance detector arrays in various vapor classification tasks. This approach allowed quantification ability a 14-element carbon black-insulating polymer composite chemiresistors distinguish between members set 19 solvent vapors, some which vary widely chemical properties (e.g., methanol benzene) others are very similar...

External quantum efficiency and transient photocapacitance (TPC) spectra were obtained for perovskite solar cells with methylammonium lead triiodide absorbers formed by either dip or vapor conversion. These measurements reveal an extended band of sub-gap states in all the devices studied. The defect is best fit a pair defects, appearance signal indicates that at least one observed defects absorber. largest density show lowest short-circuit current open-circuit voltage slow,...

The solution phase n-doping of C60 and PCBM with tetrabutylammonium fluoride is shown to occur via an initial chemical reaction followed by electron transfer a second fullerene molecule. formation ionic radical intermediate species has significant implications for the use ionically functionalized materials as electron-selective interface layers in OPVs.

A detailed study of current transport at the Schottky-type n-InP | poly(pyrrole) interface is presented. At room temperature, this exhibits an average quality factor n=1.02±0.02, a C–V barrier height qφbCV=0.78±0.01 eV, and surface recombination velocity over two orders-of-magnitude slower than ideal metal interfaces. These latter parameters imply effective 0.9 which among highest values ever reported for diode. The increases monotonically with decreasing temperature reaching value 1.23 98...

Although in principle semiconductor-metal (Schottky) diodes should be tunable by changing the work function of metal, such flexibility cannot achieved a single device and practice is often limited interfacial states that cause Fermi-level pinning. A diode reported based on hybrid inorganic-organic, n-indium phosphide&cjs3539;poly- (pyrrole)&cjs3539;nonaqueous electrolyte architecture. By electrochemically manipulating conjugated polymer poly(pyrrole), turn-on voltage (more precisely, forward...

Dopant counterion diffusion has made the conjugated polymer pn homojunction a challenging target for decades. We report electrochemical fabrication of polyacetylene based on internally compensated forms where dopant counterions are covalently bound to backbone. After drying under vacuum, junction exhibits diode behavior with ratio forward reverse current at 2 V being 7. Despite such modest behavior, fabricated is significant because it demonstrates utility internal compensation in metastable...

We demonstrate a quantum-dot microcavity by coupling core–shell semiconductor nanocrystals to fused-silica microsphere. show that the composite can feature Q factors of order 108, providing model system for investigating cavity QED and microlasers at level single quantum dots.

Spectral hole burning reveals a sharp zero-phonon line (ZPL) as well discrete acoustic phonon sidebands in CdSe nanocrystals. The ZPL linewidth obtained from the spectral depends strongly on measurement time scale, reflecting effects of diffusion. nonlinear optical allows us to suppress diffusion leading narrow $6\ensuremath{\mu}\mathrm{eV}.$

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation of bis(tetrabutylammonium) octa(.mu.3-chloro)hexakis(trifluoromethanesulfonato)-octahedro-hexamolybdate(2-), (Bu4N)2[Mo6Cli8(CF3SO3)a6]: a versatile starting material for substituted molybdenum(II) clusters containing the [Mo6Cli8]4+ coreDean H. Johnston, Dennis C. Gaswick, Mark Lonergan, Charlotte L. Stern, and Duward F. ShriverCite this: Inorg. Chem. 1992, 31, 10, 1869–1873Publication Date (Print):May 1, 1992Publication History...

Für mehr Akzeptanz! 2,8-Disubstituierte Indeno[1,2-b]fluorene (siehe Strukturen; TIPS=Triisopropylsilyl) wurden synthetisiert und charakterisiert. Elektrochemische, optische theoretische Daten zeigen, dass diese Elektronenakzeptor-Kohlenwasserstoffe niedrige HOMO- LUMO-Energien aufweisen ihre Bandlücken mit denen gebräuchlicher organischer n-Halbleitermaterialien vergleichbar sind.

We analytically calculate fundamental limits on the open-circuit voltage (Voc) of a solar cell imposed by contact selectivity and recombination. To do so, we consider simple model consisting only carrier generation in an absorber charge transfer to its contacts enabling algebraic solution for relevant partial currents calculation contact-determined Voc. An expression Voc is determined assuming at linearly depend product appropriate equilibrium exchange current density excess concentration...

The interface between the inorganic semiconductor p-type InP and conjugated polymer poly(pyrrole) exhibits electrical characteristics of a Schottky diode. Capacitance–voltage measurements yield an average barrier height 0.62 ± 0.01 eV at temperature T =298 K. At same temperature, empirical quality factor, extracted from current–voltage measurements, is near unity. However, show deviation thermionic emission theory as reduced, witnessed by increase factor curvature in Richardson plot. Such...

Charge transport at conjugated polymer interfaces with metals and inorganic semiconductors is reviewed. Experiments on the equilibrium properties DC current-voltage behavior of four specific classes interfaces-metal-doped polymer, semiconductor-doped metal-intrinsic polymer/electrolyte-are discussed. To facilitate this discussion, classic models equilibration ideal between electronic conductors free-electron are introduced their limitations Particular emphasis placed charge distributions...

The significance of gate electrode processes to the transfer characteristics electrochemical transistors is demonstrated using a device based on polyacetylene ionomer. Two regimes operation are identified. first involves conventional redox process where two Faradaic balance: oxidative doping polymer modulate conductivity coupled reduction at electrode. second nonconventional hybrid mode operation: charging an ionic double layer electrode, which non-Faradaic process. implications these design...