Investigation of molecular beam epitaxial NdF[sub 3]/Si(111) heterostructures by atomic force microscopy and x-ray diffractometry

Author(s):  
J. M. Ko ◽  
S. D. Durbin ◽  
T. Fukuda ◽  
K. Inaba
2019 ◽  
Vol 53 (4) ◽  
pp. 512
Author(s):  
Е.А. Емельянов ◽  
А.В. Васев ◽  
Б.Р. Семягин ◽  
М.Ю. Есин ◽  
И.Д. Лошкарев ◽  
...  

The influence of substrate misorientation degree on the composition and morphology of layers during molecular-beam epitaxy of InAsxSb1−x solid solutions on the GaAs surface was studied. The GaAs wafers with orientation (001), which were miscuted in the [110] direction by 0, 1, 2 and 5◦, were used as substrates. The growth of heterostructures was performed for temperatures of 310◦C and 380◦C (lower and upper boundaries for the temperature range of structurally perfect InAsx Sb1−x films formation, respectively). The influence of the arsenic molecular form (As2 or As4) on the composition of layers was studied. Studies of composition and structural properties were carried out using high-resolution X-ray diffractometry (HRXRD) and atomic force microscopy (AFM). It was established that in the series of misorientation from 0 to 5◦ the arsenic fraction x increases consecutively with the use of both flux of As2 and flux of As4 molecules. When the flux of As2 molecules is used, the fraction x increases insignificantly (in 1.05 times) with a rise of misorientation degree, but when using As4 molecules, x increases in 1.75 times. The increase of the growth temperature leads to the rise of the arsenic fraction in the solid solution. The morphology of the surface improves during increasing of misorientation degree at a low growth temperature and degrades at high temperatures.


1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.


2018 ◽  
Vol 51 (2) ◽  
pp. 246-253
Author(s):  
Dev Raj Chopra ◽  
Justin Seth Pearson ◽  
Darius Durant ◽  
Ritesh Bhakta ◽  
Anil R. Chourasia

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