Effects of Ytterbium Addition on Liquid Phase Epitaxial Growth of InGaAs/InP Heterostructures

1993 ◽  
Vol 301 ◽  
Author(s):  
A. Davis ◽  
H.M. Dauplaise ◽  
J.P. Lorenzo ◽  
G.O. Ramseyer ◽  
J. A. Horrigan

ABSTRACTWe have investigated the effects of Yb addition to melts used for the growth of InGaAs/InP heterostructures by liquid phase epitaxy. Our results indicate that impurities in the Yb play an important role in determining the changes in electrical properties observed in the epilayers after Yb treatment of the melt. We have examined samples using double-crystal x-ray diffractometry, photoluminescence, Hall/van der Pauw measurements, and secondary-ion mass spectroscopy. After Yb treatment, the residual carrier concentrations of the epilayers were reduced by more than one order of magnitude and the samples luminesced more strongly; while the lattice matching and crystal quality of the epilayers were not measurably affected by the Yb. There was a smaller-thanexpected ncrease in the 77K mobility and a marked increase in the compensation ratio of the epilayers grown after the addition of Yb to the melt. We believe the Yb is both acting as a scavenging agent in the melt, combining with impurities that otherwise would have been incorporated in the epilayers, and introducing deep level impurities of its own, which are incorporated into the grown layers.

1986 ◽  
Vol 90 ◽  
Author(s):  
I. B. Bhat ◽  
N. R. Taskar ◽  
J. Ayers ◽  
K. Patel ◽  
S. K. Ghandhi

ABSTRACTCadmium telluride layers were grown on InSb substrates by organometallic vapor phase epitaxy and examined using secondary ion mass spectrometry (SIMS), photoluminescence (Pb) and double crystal x-ray diffraction (DCD). The substrate temperature and the nature of the surface prior to growth are shown to be the most important parameters which influence the quality of CdTe layers. Growth on diethyltelluride (DETe) stabilized InSb substrates resulted in CdTe growth with a misorientation of about 4 minutes of arc with respect to the substrates. On the other hand, the grown layers followed the orientation of the substrates when a dimethylcadmium (DMCd) stabilized InSb was used. Growth at 350°C resulted in the smallest x-ray rocking curve (DCRC) full width at half maximum (FWHM) of about 20 arc seconds.


1984 ◽  
Vol 41 ◽  
Author(s):  
S J Barnett ◽  
B K Tanner ◽  
G. T. Brown

AbstractThe high intensity and large beam size of a synchrotron radiation source have been exploited in order to obtain double crystal X-ray topographs of whole 2in. and 3in. slices of semi-insulating LEC GaAs single crystals. Exposure times, typically 30 minutes for high resolution topographs, are at least one order of magnitude down on those required when using a conventional source. Variations in relative lattice parameter and lattice tilt have been measured as a function of position on the slice. The defect structure has been imaged and dislocations are seen in cellular configurations, slip bands and linear arrays (lineage), the latter of which are shown to be associated with small lattice tilts, typically 30”. The defect structure revealed on the topographs has been correlated with 1μm infrared absorption micrographs which are believed to represent the concentration of the dominant deep level EL2.


1988 ◽  
Vol 116 ◽  
Author(s):  
K. Uchida ◽  
Y. Kohama ◽  
M. Tajima ◽  
T. Soga ◽  
T. Jimbo ◽  
...  

AbstractGaP crystals are grown on Si substrates by MOCVD. Double crystal X-ray diffraction indicates that the crystal quality of GaP layers greatly improves when AsH3 is supplied before growth. The FWHM of (400) diffraction peak of the GaP layer decreases as the thickness increases and the best FWHM of 112.5 arcs is obtained at a thickness of 5 μm. The GaP/Si interface is characterized using secondary ion mass spectroscopy (SIMS) to demonstrate the effect of AsH3.


1982 ◽  
Vol 43 (C5) ◽  
pp. C5-3-C5-10 ◽  
Author(s):  
M. C. Joncour ◽  
J. L. Benchimol ◽  
J. Burgeat ◽  
M. Quillec

Author(s):  
Gennadiy Valentinovich Alexeev ◽  
Elena Igorevna Verboloz

The article focuses on the process of intensive mixing of liquid phase in the tin during high-temperature sterilization, i.e. sterilization when temperature of the heat carrier reaches 150-160°C. It has been stated that for intensification of the thermal process during sterilization of tinned fish with liquid filling it is preferable to turn a tin from bottom to top. This operation helps to increase the driving power of the process and to shorten warming time. Besides, high-temperature sterilization carried out according to experimental modes, where the number of tin turnovers is calculated, greatly shortens processing time and improves quality of the product. In this case there is no superheating, all tins are evenly heated. The study results will contribute to equipment modernization and to preserving valuable food qualities.


RSC Advances ◽  
2020 ◽  
Vol 10 (67) ◽  
pp. 40658-40662
Author(s):  
Norihiro Suzuki ◽  
Chiaki Terashima ◽  
Kazuya Nakata ◽  
Ken-ichi Katsumata ◽  
Akira Fujishima

An anatase-phase mesoporous titania thin film with a pseudo-single-crystal framework was facilely synthesized by an inexpensive chemical process.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 839
Author(s):  
Mitchell Kent ◽  
William Rooney

Interest in the use of popped sorghum in food products has resulted in a niche market for sorghum hybrids with high popping quality but little work has been done to assess the relative effects of field processing methods of grain on popping quality. This study evaluated the relative effects of harvest moisture and threshing methods on the popping quality of sorghum grain. A grain sorghum hybrid with good popping quality was produced during two different years in Texas wherein it was harvested at two moisture levels (low and high) and grain was removed from panicles using five different threshing methods (hand, rubber belt, metal brushes and two metal concave bar systems). Years, harvest moisture content and threshing method influenced all three popping quality measurements (popping efficacy, expansion ratio and flake size), but threshing method had an order of magnitude larger effect than either moisture level or year. While many of the interactions were significant, they did not influence the general trends observed. As such, the threshing methods with less direct impact force on the grain (hand and rubber belt) had higher popping quality than those samples threshed with greater impact force on the grain (metal-based systems). The popping quality differences between threshing system are likely due to a reduction in kernel integrity caused by the impacts to the kernel that occurred while threshing the grain. The results herein indicate that field processing of the grain, notably threshing method has significant impacts on the popping quality and should be taken into consideration when grain sorghum is harvested for popping purposes.


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