Impact of near-surface native point defects, chemical reactions, and surface morphology on ZnO interfaces

Author(s):  
D. R. Doutt ◽  
C. Zgrabik ◽  
H. L. Mosbacker ◽  
L. J. Brillson
1998 ◽  
Vol 527 ◽  
Author(s):  
B. Aufray ◽  
H. Giordano ◽  
V. Petrova ◽  
D. N. Seidman

ABSTRACTWe present a scanning tunneling microscopy (STM) study, performed at different elevated temperatures, on the influence of Sb surface segregation on the morphology of the (111) surface of a Cu-0.45 at.% Sb solid-solution single-crystal; the surface was initially cleaned at room temperature by Ar+ ion sputtering. Unexpectedly, when the temperature is increased from room temperature to 380°C, the typical (111) surface morphology, obtained after sputtering, evolves in two very different manners that depend on the heating rate. If the heating rate is rapid (approximately a few minutes), it evolves to a structure with large terraces, whereas if it is slow (about 10 hours) the morphology does not evolve -- i.e., it is frozen. These unexpected results are interpreted in terms of excess subsurface point defects (vacancies and self-interstitials) created during ion bombardment, which are mobile and can mediate Sb diffusion at low temperatures. This is mainly on step edges, but the point defects can precipitate out of solution, for a rapid heating rate, thereby forming small secondary clusters in the near-surface region, in which Sb atoms are trapped.


2011 ◽  
Vol 509 ◽  
pp. S658-S661 ◽  
Author(s):  
Lars Ismer ◽  
Anderson Janotti ◽  
Chris G. Van de Walle

1990 ◽  
Vol 216 ◽  
Author(s):  
M.A. Berding ◽  
A. Sher ◽  
A.-B. Chen

ABSTRACTNative point defects play an important role in HgCdTe. Here we discuss some of the relevant mass action equations, and use recently calculated defect formation energies to discuss relative defect concentrations. In agreement with experiment, the Hg vacancy is found to be the dominant native defect to accommodate excess tellurium. Preliminary estimates find the Hg antisite and the Hg interstitial to be of comparable densities. Our calculated defect formation energies are also consistent with measured diffusion activation energies, assuming the interstitial and vacancy migration energies are small.


2006 ◽  
Vol 527-529 ◽  
pp. 717-720 ◽  
Author(s):  
Sashi Kumar Chanda ◽  
Yaroslav Koshka ◽  
Murugesu Yoganathan

A room temperature PL mapping technique was applied to establish the origin of resistivity variation in PVT-grown 6H SiC substrates. A direct correlation between the native defect-related PL and resistivity was found in undoped (V-free) samples. In vanadium-doped samples with low vanadium content, the resistivity showed a good correlation with the total PL signal consisting of contributions from both vanadium and native point defects. Well-known UD1 and UD3 levels were revealed by low-temperature PL spectroscopy. Some correlation was observed between these low-temperature PL signatures and the resistivity distribution.


2017 ◽  
Vol 147 (2) ◽  
pp. 024707 ◽  
Author(s):  
Tingting Wang ◽  
Guiwu Liu ◽  
Yuanyuan Li ◽  
Haigang Hou ◽  
Ziwei Xu ◽  
...  

2015 ◽  
Vol 91 (4) ◽  
Author(s):  
V. Wang ◽  
Y. Kawazoe ◽  
W. T. Geng

2017 ◽  
Vol 128 ◽  
pp. 103-108
Author(s):  
M.H.N. Assadi ◽  
H. Katayama-Yoshida

2000 ◽  
Vol 5 (S1) ◽  
pp. 287-293
Author(s):  
J. A. Chisholm ◽  
P. D. Bristowe

We report on the interaction of native point defects with commonly observed planar defects in GaN. Using a pair potential model we find a positive binding energy for all native defects to the three boundary structures investigated indicating a preference for native defects to form in these interfaces. The binding energy is highest for the Ga interstitial and lowest for vacancies. Interstitials, which are not thought to occur in significant concentrations in bulk GaN, should form in the (11 0) IDB and the (10 0) SMB and consequently alter the electronic structure of these boundaries.


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