Photoreflectance study of the surface Fermi level at (001) n‐ and p‐type GaAs surfaces

1992 ◽  
Vol 10 (1) ◽  
pp. 131-136 ◽  
Author(s):  
X. Yin ◽  
H‐M. Chen ◽  
F. H. Pollak ◽  
Y. Chan ◽  
P. A. Montano ◽  
...  
1992 ◽  
Vol 260 ◽  
Author(s):  
Changyoung Kim ◽  
Paul L. King ◽  
Piero Pianetta

ABSTRACTA photoelectron microscope operating with a retarding field analyzer has been used to exploit core level energy shifts due to band bending in order to directly image Fermi level variations on n- and p-type cleaved GaAs(110) surfaces. Fermi level maps resolved to better than 10 um indicate lateral variations in the surface Fermi level which are often quite abrupt. In agreement with earlier, lower resolution work [1], Fermi level topography is found to be highly correlated with surface roughness as characterized by SEM, optical microscope and stylus profi lometer. The largest defect derived pinnings encountered to date resut in the Fermi level lying 0.5 eV above the VBM for both n- and p-type GaAs. Low coverage In evaporations have the. effect of reducing Fermi level contrast as Fermi levels in formerly unpinned regions move into the gap.


2014 ◽  
Vol 5 (1) ◽  
Author(s):  
M. G. Kibria ◽  
S. Zhao ◽  
F. A. Chowdhury ◽  
Q. Wang ◽  
H. P. T. Nguyen ◽  
...  

2002 ◽  
Vol 41 (Part 1, No. 2B) ◽  
pp. 1067-1071 ◽  
Author(s):  
Tetsuo Kurayama ◽  
Gennki Sano ◽  
Masamichi Sakai

2009 ◽  
Vol 79-82 ◽  
pp. 1253-1256 ◽  
Author(s):  
Li Guan ◽  
Qiang Li ◽  
Xu Li ◽  
Jian Xin Guo ◽  
Bo Geng ◽  
...  

In the present paper, the lattice structure, band structure and density of state of pure and P-doped ZnO are calculated by first-principle method based on density functional theory. By analyzing the Mulliken charge overlap population and bond length, it is found that the bond of P-Zn is longer and stronger than O-Zn bond for PO-ZnO. But for PZn-ZnO, the O-P bond becomes shorter and more powerful than O-Zn bond. Also, weak O-O bonds are formed in this case. Our results show that the final total energy of PO-ZnO is lower than PZn-ZnO. The lattice structure of PO-ZnO is more stability than PZn-ZnO. For PO-ZnO, The Fermi level moves into the valence band, which expresses that the holes appear on the top of valence band and thus the PO-ZnO exhibits p-type conductivity. For PZn-ZnO, the Fermi level moves up to the conductor band and the total density of states shifts to the lower energy region, thus PZn-ZnO shows the n-type conductivity.


2009 ◽  
Vol 156-158 ◽  
pp. 145-148 ◽  
Author(s):  
Daniel Kropman ◽  
E. Mellikov ◽  
K. Lott ◽  
Tiit Kärner ◽  
Ivo Heinmaa ◽  
...  

The results of investigation of the point defect generation and interaction with impurities in the Si-SiO2 system during the process of its formation by means of electron paramagnetic resonance (EPR) and nucleous magnetic resonance (NMR) technique are presented. It has been shown that the diference in point defects interaction with hydrogen at the Si-SO2 interface with n- and p-type conductivity are connected with the sign of hydrogen ions incorporation dependence on the Fermi level position in accordance with the proposed model. The interface properties may be improved by laser irradiation.


Author(s):  
Tien Dat Ngo ◽  
Min Sup Choi ◽  
Myeongjin Lee ◽  
Fida Ali ◽  
Won Jong Yoo

A technique to form the edge contact in two-dimensional (2D) based field-effect transistors (FETs) has been intensively studied for the purpose of achieving high mobility and also recently overcoming the...


2020 ◽  
Vol 7 (12) ◽  
pp. 200723
Author(s):  
Hai Duong Pham ◽  
Wu-Pei Su ◽  
Thi Dieu Hien Nguyen ◽  
Ngoc Thanh Thuy Tran ◽  
Ming-Fa Lin

The essential properties of monolayer silicene greatly enriched by boron substitutions are thoroughly explored through first-principles calculations. Delicate analyses are conducted on the highly non-uniform Moire superlattices, atom-dominated band structures, charge density distributions and atom- and orbital-decomposed van Hove singularities. The hybridized 2 p z –3 p z and [2s, 2 p x , 2 p y ]–[3s, 3 p x , 3 p y ] bondings, with orthogonal relations, are obtained from the developed theoretical framework. The red-shifted Fermi level and the modified Dirac cones/ π bands/ σ bands are clearly identified under various concentrations and configurations of boron-guest atoms. Our results demonstrate that the charge transfer leads to the non-uniform chemical environment that creates diverse electronic properties.


2008 ◽  
Vol 93 (4) ◽  
pp. 041913 ◽  
Author(s):  
Houssam Chouaib ◽  
Catherine Bru-Chevallier ◽  
Aleksandra Apostoluk ◽  
Wojciech Rudno-Rudzinski ◽  
Melania Lijadi ◽  
...  

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