Growth of High Quality Single Crystal ZnO Films on Sapphire by Pulsed Laser Ablation

1998 ◽  
Vol 526 ◽  
Author(s):  
A.K. Sharma ◽  
K. Dovidenko ◽  
S. Oktyabrsky ◽  
D.E. Moxey ◽  
J.F. Muth ◽  
...  
Keyword(s):  
Single Crystal ◽  
Defect Density ◽  
Pulsed Laser ◽  
Growth Conditions ◽  
Oxygen Stoichiometry ◽  
Zno Films ◽  
High Quality ◽  
High Quality Single Crystal ◽  
Transmission Electron ◽  
Order Of Magnitude

AbstractThe structural and optical characterizations of single crystal zinc oxide films on sapphire have been performed. The ZnO films were deposited by pulsed laser deposition in an oxygen environment. These films were annealed in oxygen for further improvement in the oxygen stoichiometry. Both as-deposited and oxygen annealed films were high quality single crystal as characterized by X-ray diffraction and transmission electron microscopy. The defect density, comprised mainly of dislocations and stacking faults, was low as compared to high quality films of III-nitrides deposited on sapphire. Under these growth conditions, the ZnO films grow two dimensionally on sapphire as opposed to GaN which grows three dimensionally. The band edge photoluminescence was found to be dominant, and an order of magnitude higher in the annealed films. Transmission measurements and the electrical resistivity of the annealed films also show the films were of high quality after annealing. It is envisaged that these improvements in the quality of the ZnO films occur as a result of reduction of oxygen vacancies and the density of point defects.

MOCVD Growth and Characterization of High-Quality ZnSe on GaAs

1994 ◽  
Vol 340 ◽  
Author(s):  
J. C. Chen ◽  
Bing Yang ◽  
F. Semendy ◽  
W. W. Clark ◽  
P. R. Boyd ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Defect Density ◽  
Growth Conditions ◽  
Misfit Dislocations ◽  
High Quality ◽  
Double Crystal ◽  
X Ray ◽  
Mocvd Growth ◽  
Order Of Magnitude

ABSTRACTHigh-quality ZnSe epilayers on GaAs substrates have been grown by MOCVD. Diethylzinc (DEZn) and diethylselenide (DESe) were used as source materials. Growth studies were done at 400°C under different growth conditions in an atmospheric pressure MOCVD reactor. The as-grown ZnSe epilayers were characterized by a wide variety of techniques, such as double crystal x-ray diffraction, low-temperature photoluminescence (PL), transmission electron microscopy (TEM), secondary ion mass spectrometry (SIMS), and scanning electron microscopy (SEM).The results show excellent structural and optical properties of ZnSe. The best material was grown on undoped GaAs at the VI/II ratio near unity. The full-width-at-half-maximum (FWHM) of ZnSe (∼0.2/μm thick) x-ray peak as low as 90 arc seconds was achieved. TEM results also show very low defect density. The density of stacking faults is less than 105/cm2 which is four orders of magnitude less than that of samples grown by conventional MBE [J. Petruzzello et al. J. Appl. Phys. 63, 2299 (1988)] and MOCVD [J.L. Batstone et al. Philos. Mag A, 66, 609, 1992]. The spacing between misfit dislocations is between 5 to 10,μm which is one order of magnitude larger than that of reported sample of comparable thickness.

Materials with Dirac Loops: A Potential Solution for Next-generation Electronics

2021 ◽  
Vol 1 ◽  
Keyword(s):  
Electronic Structure ◽  
Single Crystal ◽  
Potential Solution ◽  
Next Generation ◽  
Rhenium Oxide ◽  
High Quality ◽  
High Quality Single Crystal

A high-quality single crystal of rhenium oxide shows significantly large magnetoresistance, potentially originating from a unique electronic structure called “hourglass Dirac chain” protected by the symmetry of the crystal.

Epitaxy of High-Quality Single-Crystal Hexagonal Perovskite YAlO3 on GaAs(111)A Using Laminated Atomic Layer Deposition

2019 ◽  
Vol 19 (4) ◽  
pp. 2030-2036 ◽  
Author(s):  
Lawrence Boyu Young ◽  
Chao-Kai Cheng ◽  
Keng-Yung Lin ◽  
Yen-Hsun Lin ◽  
Hsien-Wen Wan ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Single Crystal ◽  
Atomic Layer ◽  
High Quality ◽  
High Quality Single Crystal ◽  
Layer Deposition

Deposition and surface characterization of high quality single crystal GaN layers

1993 ◽  
Vol 73 (6) ◽  
pp. 3108-3110 ◽  
Author(s):  
M. Asif Khan ◽  
J. N. Kuznia ◽  
D. T. Olson ◽  
R. Kaplan
Keyword(s):  
Single Crystal ◽  
Surface Characterization ◽  
High Quality ◽  
High Quality Single Crystal

The Shallow Implantation of Bismuth During the Growth of Bismuth Nanocrystals in Al2O3 by Pulsed Laser Deposition

2003 ◽  
Vol 780 ◽  
Author(s):  
A. Suárez-García ◽  
J-P. Barnes ◽  
R. Serna ◽  
A. K. Petford-Long ◽  
C. N. Afonso ◽  
...  
Keyword(s):  
Energy Density ◽  
Cross Section ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Laser Energy Density ◽  
X Ray ◽  
Continuous Layer ◽  
Transmission Electron ◽  
Order Of Magnitude

AbstractThe effect of the laser energy density used to deposit Bi onto amorphous aluminum oxide (a-Al2O3) on the growth of Bi nanocrystals has been investigated using transmission electron microscopy of cross section samples. The laser energy density on the Bi target was varied by one order of magnitude (0.4 to 5 J cm-2). Across the range of energy densities, in addition to the Bi nanocrystals nucleated on the a-Al2O3 surface, a dark and apparently continuous layer appears below the nanocrystals. Energy dispersive X-ray analysis on the layer have shown it is Bi rich. The separation from the Bi layer to the bottom of the nanocrystals on top is consistent with the implantation range of Bi species in a-Al2O3. As the laser energy density increases, the implantation range has been measured to increase. The early stages of the Bi growth have been analyzed in order to determine how the Bi implanted layer develops.

scholarly journals Fabrication of high-quality single-crystal Cu thin films using radio-frequency sputtering

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Seunghun Lee ◽  
Ji Young Kim ◽  
Tae-Woo Lee ◽  
Won-Kyung Kim ◽  
Bum-Su Kim ◽  
...  
Keyword(s):  
Thin Films ◽  
Radio Frequency ◽  
Single Crystal ◽  
High Quality ◽  
High Quality Single Crystal ◽  
Radio Frequency Sputtering

Tem Characterization of ZnO and AIN/ZnO Thin Films Grown on Sapphire

1998 ◽  
Vol 526 ◽  
Author(s):  
K. Dovidenko ◽  
S. Oktyabrsky ◽  
A. K. Sharma ◽  
J. Narayan
Keyword(s):  
Single Crystal ◽  
Pulsed Laser Deposition ◽  
Basal Plane ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Zno Films ◽  
Threading Dislocation ◽  
Epitaxial Relationship ◽  
Spinel Layer ◽  
Plan View

AbstractThin (~ 250 nm) films of ZnO grown by pulsed laser deposition on basal plane of sapphire were studied by transmission electron microscopy (TEM). Plan-view TEM study proved the films to be single crystal with the following epitaxial relationship with the substrate: (0001)znO || (0001)sap with the 30 30° in-plane rotation - [0110]ZnO || [1210]sap. Dislocations lying mostly in basal plane of ZnO and aligned along both <:1010> and <1120> directions having b=1/3[1120] were found. ZnO films were found to have layered growth morphology contrary to columnar morphology of III-nitrides. Consequently, the threading dislocation density in ZnO films (opposing to the AIN and GaN) drops very fast with the thickness: down to 107cm-2 at ~ 250 nm. The effect of post-annealing (which caused significant improvement in electrical and optical properties) on the microstructure of ZnO films was also studied. Contrary to the atomically sharp and clean interface in the as-deposited films, the post-annealed ZnO/sapphire interface contained reacted layer of 30 - 60 A thickness. The structure of the interlayer was determined to be ZnAl2O4 (spinel). The formation of this single crystal spinel layer did not cause deterioration of the ZnO film structure or properties. We have also explored the possibilities of using ZnO as a buffer for III-nitride growth. The epitaxial AIN films were grown on top of the ZnO layer by pulsed laser deposition. Thin (20 -60 A) interfacial reaction layer (also spinel ZnAm2O4) was observed between AIN and ZnO. Formation of this interlayer is studied in conjunction with the AIN epitaxy and the characteristics of defects and interfaces.

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