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Describes a study of remedial, freshman English classes that analyzed students' ability, motivation to attend classes, and career choices and compared these factors to achievement levels or grades. (MKM)

The need for and the limits of flexibility in college reading and study skills instruction are discussed with regard to the diversity of student population and theories on the reading process. (HTH)

Reviews research dealing with creativity as it applies to the process of reading. (FL)

An independently controlled, three-color, organic light-emitting device was constructed with a vertically stacked pixel architecture that allows for independent tuning of color, gray scale, and intensity. The 12-layer device structure consists of sequentially stacked layers of metal oxide, amorphous organic, crystalline organic, and metal thin films deposited by a combination of thermal evaporation and radio-frequency sputtering. Each of the three addressable colors is sufficiently bright for flat panel video display applications. A novel inverted structure is used for the middle device in the stack to lower the maximum drive voltage of the compound pixel., Organic light-emitting devices (OLEDs) (1, 2), in particular vacuum-deposited OLEDs, have sufficient brightness, range of color (3-5), and operating lifetimes (6) to make them a possible alternative to liquid crystal--based [...]

Several new iridium based cyclometalated complexes were investigated as phosphorescent dopants for molecularly doped polymeric organic light-emitting diodes. Specifically, the complexes used in this study were iridium (III) bis(2-phenylpyridinato-N,C[sup 2']) (acetylacetonate) [ppy], iridium (III) bis(7,8-benzoquinolinato-N,C[sup 3']) (acetylacetonate) [bzq], iridium (III) bis(2-phenylbenzothiazolato-N,C[sup 2']) (acetylacetonate) [bt], iridium (III) bis(2-(2&prime-; naphthyl)benzothiazolato-N, C[sup 2']) (acetylacetonate) [bsn] and iridium (III) bis(2-(2'-benzo[4,5-a]thienyl)pyridinato-N,C[sup 3']) (acetylacetonate) [btp]. Single layer devices of doped polyvinylcarbazole: 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole give maximum external quantum efficiencies that varied from 3.5% for the ppy dopant to 0.4% for the btp dopant. Several different device heterostructure architectures were explored, and the best quantum efficiency of the devices reached 4.2% for the heterostructures. [ABSTRACT FROM AUTHOR]

Interactions between hole-transporting carbazole groups and electron-transporting 1,3,4-oxadiazole groups were studied by photoluminescence and electroluminescence (EL) spectroscopy, in blends of poly(N-vinylcarbazole) with 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PVK:PBD) and in random copolymers with carbazole and oxadiazole groups attached as side chains. Different excited-state complexes form in the blends, which exhibit exciplexes, and in the copolymers, which manifest electroplexes, due to topological constraints on the position of carbazole and oxadiazole units in the polymer. Both types of complex red-shift the EL spectra of the matrices compared with pure PVK homopolymer, although the shift is significantly greater for the electroplex. The presence of these complexes has a profound effect on the external quantum efficiency of dye-doped organic light-emitting diodes employing the blends or copolymers as matrices, as it strongly affects the efficiency of Förster energy transfer from the matrix to the dye. Single-layer devices doped with either coumarin 47 (C47), coumarin 6 (C6), or nile red (NR) were compared. Among the three dye-doped PVK:PBD devices, C6 doping yields the highest efficiency, while NR doping produced the most efficient copolymer devices, consistent with the degree of overlap between the EL spectrum of the matrix material and the absorption spectrum of the dye. [ABSTRACT FROM AUTHOR]

We demonstrate very high efficiency electrophosphorescence in organic light-emitting devices employing a phosphorescent molecule doped into a wide energy gap host. Using bis(2-phenylpyridine)iridium(III) acetylacetonate [(ppy)[sub 2]Ir(acac)] doped into 3-phenyl-4(1′-naphthyl)-5-phenyl-1,2,4-triazole, a maximum external quantum efficiency of (19.0±1.0)% and luminous power efficiency of (60±5) lm/W are achieved. The calculated internal quantum efficiency of (87±7)% is supported by the observed absence of thermally activated nonradiative loss in the photoluminescent efficiency of (ppy)[sub 2]Ir(acac). Thus, very high external quantum efficiencies are due to the nearly 100% internal phosphorescence efficiency of (ppy)[sub 2]Ir(acac) coupled with balanced hole and electron injection, and triplet exciton confinement within the light-emitting layer. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A method for studying the degradation of organic light emitting devices (OLEDs) in real time is described. Transparent OLEDs allow for the spatial correlation of cathode topographic images with optical images (transmission, photoluminescence, and electroluminescence) of the devices throughout the degradation process. In this study we focused on the evolution of nonemissive, “dark” spots during device operation. We conclude that the electroluminescent dark spots originate as nonconductive regions at the cathode/organic interface and expand or grow as a result of exposure to atmosphere. We propose a mechanism of dark spot growth involving aerobic oxidation of the cathode/organic interfacial region, leading to a highly resistive, carrier blocking interface at the dark spot locations. No initial defects on the cathode surface, which might be responsible for the formation of dark spots, were detected by atomic force microscopy. Structural changes, such as degradation of organic materials and the cathode surface, occur well after the formation and growth of the dark spots. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A series of five platinum(II) complexes are described that have illustrated benzannulation of aromatic molecules, which is used to blue or red-shift absorption and emission bands. The studies have shown that either a blue shift or a red shift in absorption and emission maxima, relative to their respective nonbenzannulated compounds is observed for this series of molecules that has depended on the site of benzannulation.

A solution-phase route employing stoichiometric amounts of di-tert-butyl diselenide as a novel and facile selenium source is utilized to synthesize the nanocrystals of phase-pure tin(II) selenide (SnSe). The significantly enhanced quantum efficiency and short-circuit current density indicated that the obtained earth-abundant material could be a valuable component in future photovoltaic devices.

The Ir-based materials are prepared via metathesis reaction between halide and alkali metal salts of two cationic and three anionic Ir complexes and their electrochemical and photophysical characterization are described. The studies have shown that the soft salts have produced maximum external quantum efficiencies (EQE) and that the internal energy alignment between two ions in the soft salts is responsible for the disparate results

Solar energy can be stored efficiently using the photochromic properties of layered zirconium phosphonate/viologen compounds. These compounds create the necessary state of photoinduced charge transfer by taking on a charge-separated state that is long-lasting in air. Spectroscopic analysis shows that the resulting photoproduct is the dialkyl viologen radical cation that originates from the interlamellar region of the zirconium phosphonate.

A study was conducted to explore the dependence of the dark current of [C.sub.60]-based organic photovoltaic (OPV) cells on molecular composition and the degree of intermolecular interaction of several molecular donor materials. The study results could be used as guidelines to design materials and device architectures that maximize open circuit voltage values of OPV cell power conversion efficiency.

The photofragmentation of (3-Me-4',6'-dfppy)Pt(dpm) (dfppy = difluorophenylpyridinato; dpm = dipivaloylmethyl or 2,2,6,6-tetramethyl-3,5-heptanedionato-O,O) in a molecular beam is described. The (3-Me,4',6'-dfppy) ligand has remained intact and coordinated to platinum, but coordinated (dpm) has successively broken apart.

A double-heterostructure boron subphthalocyanine chloride (SubPc)/[C.sub.60] thin-film cells have more than twice the [V.sub.oc] as compared to conventional devices based on CuPc/[C.sub.60] cells resulting in more than doubling of the cell power conversion efficiency. By using a strongly absorbing donor material with a deep highest occupied molecular orbital, [I.sub.g] and, consequently, [V.sub.oc] are increased without a concomitant reduction in [J.sub.sc].

Complementary biosensing is demonstrated using In2O3 nanowire and single-walled carbon nanotube (SWNT) devices for the detection of prostate-specific antigen (PSA). The specificity is gained through proper surface functionalization, including a novel approach developed to covalently attach antibodies to In2O3 n-type nanowires.

The selective functionalization of an array of In2O3 nanowire (NW)-based devices is demonstrated by electrochemically activating their surfaces and then immobilizing single-strand DNA. A self-assembled monolayer (SAM) of 4-(1,4-dihydroxybenzene)butyl phosphonic acid (HQ-PA) is generated on the In2O3 NW surface.