Showing papers in "Journal of Crystal Growth in 1998"

TL;DR: Physical vapor growth in horizontal and vertical systems has been used to grow crystals of α-hexathiophene (α-6T), α-octithiophene, α-4T, pentacene, anthracene and copper phthalocyanine.

TL;DR: In this paper, the authors demonstrate working prototypes of a GaInNAs-based solar cell lattice-matched to GaAs with photoresponse down to 1 eV. This device is intended for use as the third junction of future-generation ultrahigh-efficiency three and four-junction devices.

TL;DR: In this article, the effect of the III/V ratio and substrate temperature on the growth of GaN and A1N films on Si(1 1 1) substrates by molecular beam epitaxy, where active nitrogen was generated by a radio frequency plasma source.

TL;DR: A correlation has been noted between the structures of the crystalline films and those of the crystal aggregates associated with them: i.e. films of spherulitic texture yield electron diffraction patterns characteristic of vaterite and support the growth of spheroidal vaterites, whereas calcitic single-crystal mosaic films carry rhombohedral calicite crystals as mentioned in this paper.

TL;DR: The aluminum doping was achieved by the addition of AlCl 3 ·2H 2 O and Al(NO 3 ) 3 ·9 H 2 O in the methanol solution of the chemical complex at an atomic ratio of Al/Zn=10 −3 −10 −2.

TL;DR: In this article, the threading dislocation (TD) generation was studied in the two-step metal-organic chemical vapor deposition (MOCVD) of GaN on sapphire.

TL;DR: In this article, the spectral photocurrent response of GaInNAs lattice-matched to GaAs with a bandgap of 1 eV has been measured in an electrochemical cell.

TL;DR: Spontaneous, stimulated and laser emission spectra of ZnO epitaxial layers, grown by plasma-assisted molecular beam epitaxy, are presented in this paper, where samples are found to exhibit high-intensity near band-edge emissions at room temperature.

TL;DR: In this paper, a birefringent α-BaB 2 O 4 crystal, 40mm in diameter, 35mm in height has been grown successfully in a laboratory by Czochralski method.

TL;DR: In this paper, the transformation of vaterite into calcite was investigated under conditions of constant supersaturation at 25, 35 and 45°C and pHs 8.5, 9.0 and 10.0.

TL;DR: In this paper, the quantitative model of void formation is considered to provide the nucleation temperature, density and size of voids dependent on the starting vacancy concentration and the cooling rate.

TL;DR: In this article, the complex chemistry and transport phenomena underlying metalorganic vapor phase epitaxy (MOVPE) of AlGaN; in particular, the mechanism underlying growth rate reduction at high temperatures and pressures are investigated.

TL;DR: In this article, first-principles calculations of acceptor doping in GaN and AlGaN alloys have been performed on the basis of state-of-the-art first principles calculations, showing that nitrogen vacancies are too high in energy to be incorporated during growth.

TL;DR: In this paper, the authors studied thermal annealing effects of low-temperature grown GaN (LT-GaN) on Si substrate by use of the two-step growth technique.

TL;DR: In this paper, high-power UV LEDs are obtained using an InGaN active layer with a thickness of 400 A instead of a GaN Active Layer. But the localized energy states caused by In composition fluctuation in the InGaNs active layer are related to the high efficiency of the inGaN-based LEDs.

TL;DR: In this article, the results of both mechanical and mechano-chemical polishing of the (0001) surfaces of GaN are presented, and it has been shown that the atomically flat GaN surfaces can be achieved by mechano chemical polishing.

TL;DR: In this paper, a comparative study of GaN layers grown on sapphire (0, 0,0,1) by metalorganic vapor phase epitaxy with different sappire surface preparations and carrier gas combinations is reported, which is carried out by in situ laser reflectometry measurements and ex situ transmission electron microscopy.

TL;DR: In this paper, the morphology of GaN single crystals grown in a Na flux at 750°C for 100h was observed by scanning electron microscopy, which changed from prismatic to platelet and fine grains with increasing rNa=Na/(Na+Ga) molar ratio of starting materials.

TL;DR: In this article, the dendritic evolution of an initially small nucleus is affected by a mean external flow, and the nucleus is considered to be attached to a solid wall, and it grows away from the wall into the melt.

TL;DR: In this paper, the highly c-axis oriented ZnO films were deposited on Si substrates with Zn buffer layers, and the intense cathodoluminescence, including UV, blue, and green emissions, was observed in these films at room temperature.

TL;DR: In this paper, a floating zone technique was used to grow long persistent green and blue phosphor crystals, and the results showed that the intensity and the persistent times of the phosphorescence depend on the growth atmosphere.

TL;DR: In this article, the authors reported room-temperature measurements of optical gain and gain spectra of ultraviolet emission from ZnO thin film and attributed the large gain to the modification of the spontaneous emission rate by the dielectric photonic structure of these films.

TL;DR: In this article, the authors investigated the hole concentration and the Mg related photoluminescence bands in MOCVD-grown GaN:Mg as a function of Mg-concentration.

TL;DR: In this article, a review of CdTe and CZnTe detectors for X-ray and gamma-ray spectrometers is presented, including hemispherical detectors, coplanar strip-electrode detectors and monolithic, two-dimensional segmented electrode arrays with pad sizes smaller than their thickness.

TL;DR: The formation of self-assembled CdSe quantum dots on ZnSe by a reorganization process occurring during growth interruption and thermal activation is demonstrated in this paper, where optical data yield a dot size in the 3-5 nm range and a density of 10 10 −10 11 cm −2.

TL;DR: In this article, the effect of growth temperature, growth duration, and pattern geometry on the lateral epitaxial overgrowth (LEO) of GaN stripes using a SiO 2 -masked GaN/Al 2 O 3 seed was investigated.

TL;DR: In this article, the structural evolution of the Ni-Cu system with undercooling was systematically investigated, and a thermodynamic concept, dimensionless superheating was developed to evaluate the tendency of the dendrite remelting.

TL;DR: In this article, a theoretical model based on the birth of nuclei on the surface of crystals present in the solution and their outgrowth has been developed, where the surface-born nuclei have to grow to a certain size to be detected by means of a particle analysing system or human eye.

TL;DR: In this article, the authors investigated the generation process of crystalline defects in GaP layers grown on Si substrates (GaP/Si) by molecular beam epitaxy (MBE) and migration enhanced epitaxy.

TL;DR: In this paper, the authors characterized the activation energies in AlGaN with AlN molar fraction less than 0.4 and showed that the Si donor fits quite well for the hydrogen atom like model while that of Mg acceptor deviates downward from the model.