Study of multiple-stacking growth of 1.55 μm InAs columnar quantum dots with modulated tensile-strained InGaAsP barrier layers

An investigation was performed of columnar InAs quantum dots (CQDs) with modulated tensile-strained InGaAsP barriers in which the amount of tensile strain in the upper parts was higher than in the lower parts, the dots being deposited on an InP substrate grown by metalorganic vapor phase epitaxy. The smaller tensile strain of the barrier layers in the lower parts made the photoluminescence (PL) wavelength longer while the larger tensile strain of the barrier layers in the upper parts increased the strain compensation of the CQDs. Compared to CQDs with uniformly tensile-strained barriers, 1.55 μm emission was obtained at a higher average strain of barrier layers. By utilizing modulated tensile-strained barriers, triple-stacking of 12-fold CQDs with a PL wavelength of 1.55 μm using 30-nm-thick spacer layers was achieved with good crystallinity, indicating suitability for fabrication of high density CQDs.     

J-PARC E27 Experiment to Search for a Nuclear Kaon Bound State K − pp

In the J-PARC E27 experiment, we search for a K ^? pp bound state via the d(π ⁺, K ⁺) reaction at 1.7 GeV/c at the K1.8 beam line. The binding energy and decay width of the K ^? pp bound state can be obtained in the missing mass measurement with a good energy resolution of 2 MeV/c ². A range counter array (RCA) was constructed to detect the two high-momentum protons from the K ^? pp decay and to reduce the background such as quasi-free hyperon production. Recently, we have carried out a pilot run in June, 2012. The d(π ⁺, K ⁺) missing-mass spectrum has been obtained for the first time. In this report, an overview of the E27 experiment and a preliminary result on this pilot run are presented.     

Mechanochemical synthesis,characterization and thermal study of new cocrystals of ciprofloxacin with pyrazinoic acid and p-aminobenzoic acid

Journal of Thermal Analysis and Calorimetry - Novel cocrystals of ciprofloxacin with pyrazinoic acid and p-aminobenzoic acid in the 1:1 stoichiometric ratio were obtained by the mechanochemical...     

Kinetically stabilized dibenzoborole as an electron-accepting building unit

A synthetic route to a dibenzoborole, kinetically stabilized by the 2,4,6-tri-tert-butylphenyl group, was developed, and a series of pi-extended derivatives were synthesized, which show orange-red emissions and stable electrochemical redox properties.     

Formation of Ge-diffusion-suppressed GaAs layers and InAs quantum dots on Ge/Si substrates

Crystal growth of GaAs layers and InAs quantum dots (QDs) on the GaAs layers was investigated on Ge/Si substrates using ultrahigh vacuum chemical vapor deposition. Ga-rich GaAs with anti-site Ga atoms grown at a low V/III ratio was found to suppress the diffusion of Ge into GaAs. S-K mode QD formation was observed on GaAs layers grown on Ge/Si substrates with Ga-rich GaAs initial layers, and improved photoluminescence from 1.3 μm-emitting InAs QDs was demonstrated.     

Thermal analysis (TG–DSC,DSC–microscopy and EGA) and characterization of heavy trivalent lanthanides and yttrium isonicotinates

Journal of Thermal Analysis and Calorimetry - The trivalent lanthanide isonicotinates were synthesized to obtain stoichiometry Lu(IN)3 and Ln(IN)3·2H2O (Ln?=?Tb to Lu, and Y;...