Fermi-Level Pinning at the Sb/GaAs(110) Surface Studied by Scanning Tunneling Spectroscopy

1988 ◽  
Vol 61 (4) ◽  
pp. 447-450 ◽  
Author(s):  
R. M. Feenstra ◽  
P. Mårtensson
Keyword(s):  
Fermi Level ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Fermi Level Pinning

MICROSCOPIC UNDERSTANDING AND CONTROL OF SURFACES AND INTERFACES OF COMPOUND SEMICONDUCTORS FOR MESOSCOPIC DEVICES

2000 ◽  
Vol 07 (05n06) ◽  
pp. 583-588 ◽  
Author(s):  
HIDEKI HASEGAWA
Keyword(s):  
Fermi Level ◽  
Surface Passivation ◽  
Surface States ◽  
Compound Semiconductors ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Free Surfaces ◽  
Fermi Level Pinning ◽  
Interface Control ◽  
Mesoscopic Devices

Microscopic properties of free surfaces and metal–semiconductor interfaces related to successful realization of mesoscopic devices are discussed for III–V compound semiconductors, with a particular emphasis on Fermi level pinning. Surface states causing pinning are present even on freshly MBE-grown clean (001) and (110) surfaces with well-defined surface structures. Scanning tunneling spectroscopy (STS) measurement gives anomalous spectra with large conductance gaps, and this can be explained by tip-induced local charging of surface states. Pinning on free surfaces can be considerably suppressed by a surface passivation using an ultrathin MBE-grown silicon interface control layer (Si ICL). In mesoscopic scale metal–semiconductor contacts, Fermi level pinning underneath the metal contact itself is remarkably reduced with the use of the optimum in situ electrochemical metal deposition. However, Fermi level pinning on the surrounding free surfaces has large effects on current transport and capacitance properties in such contacts.

Scanning-tunneling spectroscopy on conjugated polymer films

2003 ◽  
Vol 771 ◽  
Author(s):  
M. Kemerink ◽  
S.F. Alvarado ◽  
P.M. Koenraad ◽  
R.A.J. Janssen ◽  
H.W.M. Salemink ◽  
...  
Keyword(s):  
Polymer Films ◽  
Conjugated Polymer ◽  
Three Dimensional ◽  
Field Enhancement ◽  
Direct Consequence ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Band Alignment ◽  
Scanning Tunneling ◽  
Order Of Magnitude

AbstractScanning-tunneling spectroscopy experiments have been performed on conjugated polymer films and have been compared to a three-dimensional numerical model for charge injection and transport. It is found that field enhancement near the tip apex leads to significant changes in the injected current, which can amount to more than an order of magnitude, and can even change the polarity of the dominant charge carrier. As a direct consequence, the single-particle band gap and band alignment of the organic material can be directly obtained from tip height-voltage (z-V) curves, provided that the tip has a sufficiently sharp apex.

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