Control of electron tunnelling by fine band engineering of semiconductor potential barriers

Nanoscale ◽  
2019 ◽  
Vol 11 (44) ◽  
pp. 21376-21385 ◽  
Author(s):  
Yunhao Zhao ◽  
Chenyuan Cai ◽  
Yi Zhang ◽  
Xuebing Zhao ◽  
Yingqiang Xu ◽  
...  
Keyword(s):  
Potential Barriers ◽  
Band Engineering ◽  
Electron Tunnelling ◽  
And Diffusion

Elementary segregation and diffusion could be utilized in band engineering to modulate potential barriers for the control of electron tunnelling.

THEORETICAL STUDY OF THE ADSORPTION AND DIFFUSION OF OXYGEN ATOM ON O-TERMINATED ZnO$(000\bar 1)$ SURFACE

NANO ◽  
2014 ◽  
Vol 09 (01) ◽  
pp. 1450006 ◽  
Author(s):  
LIANG QIAO ◽  
YI ZENG ◽  
CHAOQUN QU ◽  
XIAOYING HU ◽  
LIJUN SONG ◽  
...  
Keyword(s):  
Oxygen Atom ◽  
Density Functional ◽  
Theoretical Study ◽  
Adsorbed Oxygen ◽  
Surface Relaxation ◽  
Functional Theory ◽  
Potential Barriers ◽  
Surface Work ◽  
Adsorbed Oxygen Atom ◽  
And Diffusion

The adsorption and diffusion of oxygen atom on the O -terminated ZnO [Formula: see text] surface have been systematically investigated based on first-principles density functional theory. The results show that the surface relaxation of the ZnO [Formula: see text] surface is significant. In the view of the maximization of the adsorption energy, the preferred site for the adsorption of oxygen atom is the top- O site above the oxygen atom of the first Zn – O bilayer. There is chemical bond formed between the adsorbed oxygen atom and the oxygen atom on the surface, which will result in the redistribution of the charges. The charges transfer from the ZnO surface to the adsorbed oxygen atom, which will heighten the surface potential of ZnO surface and increase the surface work function. Moreover, the diffusion of the oxygen atom on the ZnO surface has also been investigated, and the potential barriers of the diffusion have been identified to reveal the adsorption stability.

Meridional Circulation, Turbulence, and Diffusion Processes in Stars

1976 ◽  
Vol 32 ◽  
pp. 109-116 ◽  
Author(s):  
S. Vauclair
Keyword(s):  
Convection Zone ◽  
Diffusion Processes ◽  
Meridional Circulation ◽  
Diffusion Time ◽  
Work In Progress ◽  
First Results ◽  
Stellar Envelopes ◽  
And Diffusion ◽  
Turbulence And Diffusion ◽  
Hr Diagram

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.

Ordering and diffusion in II-VI/III-VI alloys with structural vacancies

1997 ◽  
Vol 101-103 (1-2) ◽  
pp. 479-487
Author(s):  
H v. Wensierski
Keyword(s):  
And Diffusion
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