Electron states at semiconductor interfaces: the intrinsic and extrinsic charge neutrality levels

1993 ◽  
Vol 344 (1673) ◽  
pp. 567-577 ◽  
Keyword(s):  
Chemical Properties ◽  
Schottky Barriers ◽  
Semiconductor Interface ◽  
Charge Neutrality ◽  
Band Offsets ◽  
Semiconductor Interfaces ◽  
Metal Atoms ◽  
Barrier Formation ◽  
Interface Barrier ◽  
Interface Geometry

A discussion is presented on the semiconductor interface barrier formation. Schottky barriers and heterojunction band offsets are analysed by means of the intrinsic and extrinsic charge neutrality levels. These levels are shown to be controlled by the interface geometry and its local chemistry. The chemical properties and the charge neutrality levels of different Schottky barriers are presented. Heterojunction band offsets are also analysed and are shown to depend on the electronegativity of the metal intralayers deposited at the interface: more electronegative metal atoms tend to reduce the hetero junction band offsets.

scholarly journals Computing with DFT Band Offsets at Semiconductor Interfaces: A Comparison of Two Methods

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1581
Author(s):  
José C. Conesa
Keyword(s):  
Significant Problem ◽  
Band Offsets ◽  
Semiconductor Interfaces ◽  
Hartree Potential ◽  
Hybrid Functionals

Two DFT-based methods using hybrid functionals and plane-averaged profiles of the Hartree potential (individual slabs versus vacuum and alternating slabs of both materials), which are frequently used to predict or estimate the offset between bands at interfaces between two semiconductors, are analyzed in the present work. These methods are compared using several very different semiconductor pairs, and the conclusions about the advantages of each method are discussed. Overall, the alternating slabs method is recommended in those cases where epitaxial mismatch does not represent a significant problem.

scholarly journals One-, Two-, and Three-Dimensional Self-Assembly of Atomically Precise Metal Nanoclusters

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1105 ◽  
Author(s):  
Ayano Ebina ◽  
Sakiat Hossain ◽  
Hikaru Horihata ◽  
Shuhei Ozaki ◽  
Shun Kato ◽  
...  
Keyword(s):  
Self Assembly ◽  
Fine Particle ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Design Guidelines ◽  
Metal Nanoclusters ◽  
Functional Nanomaterials ◽  
Physical Chemical ◽  
Metal Atoms ◽  
Fine Particle Size

Metal nanoclusters (NCs), which consist of several, to about one hundred, metal atoms, have attracted much attention as functional nanomaterials for use in nanotechnology. Because of their fine particle size, metal NCs exhibit physical/chemical properties and functions different from those of the corresponding bulk metal. In recent years, many techniques to precisely synthesize metal NCs have been developed. However, to apply these metal NCs in devices and as next-generation materials, it is necessary to assemble metal NCs to a size that is easy to handle. Recently, multiple techniques have been developed to form one-, two-, and three-dimensional connected structures (CSs) of metal NCs through self-assembly. Further progress of these techniques will promote the development of nanomaterials that take advantage of the characteristics of metal NCs. This review summarizes previous research on the CSs of metal NCs. We hope that this review will allow readers to obtain a general understanding of the formation and functions of CSs and that the obtained knowledge will help to establish clear design guidelines for fabricating new CSs with desired functions in the future.

Band offsets determination and interfacial chemical properties of the Al2O3/GaSb system

2010 ◽  
Vol 97 (16) ◽  
pp. 162109 ◽  
Author(s):  
I. Geppert ◽  
M. Eizenberg ◽  
A. Ali ◽  
S. Datta
Keyword(s):  
Chemical Properties ◽  
Band Offsets

scholarly journals Reduction of Schottky Barrier Height at Graphene/Germanium Interface with Surface Passivation

2019 ◽  
Vol 9 (23) ◽  
pp. 5014
Author(s):  
Courtin ◽  
Moréac ◽  
Delhaye ◽  
Lépine ◽  
Tricot ◽  
...  
Keyword(s):  
Fermi Level ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Barrier Height ◽  
Surface Passivation ◽  
2D Materials ◽  
Semiconductor Interface ◽  
Weakly Interact ◽  
Fermi Level Pinning ◽  
Semiconductor Interfaces

Fermi level pinning at metal/semiconductor interfaces forbids a total control over the Schottky barrier height. 2D materials may be an interesting route to circumvent this problem. As they weakly interact with their substrate through Van der Waals forces, deposition of 2D materials avoids the formation of the large density of state at the semiconductor interface often responsible for Fermi level pinning. Here, we demonstrate the possibility to alleviate Fermi-level pinning and reduce the Schottky barrier height by the association of surface passivation of germanium with the deposition of 2D graphene.

Electronic Structure of Wide Bandgap Semiconductor Interfaces: Cubic SiC/AIN, SiC/BP, C/BN

1989 ◽  
Vol 162 ◽  
Author(s):  
W. R. L. Lambrecht ◽  
B. Segall
Keyword(s):  
Interface Energy ◽  
Wide Bandgap ◽  
Type I ◽  
Type Ii ◽  
Band Offsets ◽  
Wide Bandgap Semiconductor ◽  
Semiconductor Interfaces ◽  
Densities Of States ◽  
Local Densities ◽  
Energy Of Formation

ABSTRACTThe linear muffin-tin orbital supercell band-structure method is used to calculate the interface energy of formation, band offsets and local densities of states at the latticematched (110) heterojunctions between (cubic SiC)/(cubic AIN), (cubic SiC)/(cubic BP) and (diamond C)/(cubic BN). The lowest energy bonding configuration for SiC/AIN is found to be Si to N and C to Al bonding while for SiC/BP, Si is found to bind to B and C to P. The causes for these preferred bonding configurations are explained in terms of electrostatic effects. The band offsets are found to be of type II for SiC/BP and SiC/BN and of type I for SiC/AIN.

Thermionic Refrigeration

1998 ◽  
Vol 545 ◽  
Author(s):  
G. D. Mahan
Keyword(s):  
Room Temperature ◽  
Schottky Barriers ◽  
Semiconductor Interfaces ◽  
Metal Plates ◽  
Work Functions ◽  
Vacuum Gap ◽  
Small Work

AbstractThe principles of thermionic refrigeration are explained. The simplest device is composed of two metal plates separated by a vacuum gap. This device is efficient at room temperature only for plates with small work functions (eø <0.3 eV). Small barriers are available in semiconductor-semiconductor interfaces (band off-sets) and in metal-semiconductor interfaces(Schottky barriers). An efficient refrigerator is modeled for these systems. Possible realizations are discussed.

The Calculation of Transmission Coefficients at Heterogeneous Semiconductor Interfaces: A Case Study Based on the n-InP | poly(pyrrole) Interface

2001 ◽  
Vol 679 ◽  
Author(s):  
Carrie Daniels-Hafer ◽  
Meehae Jang ◽  
Frank E. Jones ◽  
Shannon W. Boettcher ◽  
Rob Danner ◽  
...  
Keyword(s):  
Ideality Factor ◽  
Thermionic Emission ◽  
Anomalous Behavior ◽  
Semiconductor Interface ◽  
Transmission Coefficients ◽  
Semiconductor Interfaces ◽  
Capacitance Voltage ◽  
Voltage Dependent ◽  
Barrier Distribution

ABSTRACTThe n-InP | poly(pyrrole) interface is used as a case study to discuss the calculation of the transmission coefficient, describing the probability of majority carrier transfer, at a non-ideal semiconductor interface exhibiting anomalous behavior assumed to be due to a spatial distribution of barrier heights. The most notable anomaly is a weaker dependence of current on voltage than predicted by thermionic emission (i.e. quality or ideality factor greater than unity). Central to this discussion is the calculation of the equilibrium exchange current density Jo and barrier height Φb in light of a heterogeneous and potentially voltage-dependent barrier distribution. Various approaches to the measurement of Φb and Jovalid for semiconductor interfaces characterized by a uniform, voltage- and temperature-independent barrier are discussed when applied to a heterogeneous interface. In particular, the use of a capacitance-voltage measured barrier is demonstrated to result in an overestimation of κ whereas the use of a Richardson plot barrier is demonstrated to result in an underestimation. Depending on method, errors in excess of five orders-of-magnitude are observed for the n-InP | poly(pyrrole) interface under conditions where it exhibits only mildly anomalous behavior (ideality factor ≍ 1.2). The greatest confidence in the transmission coefficients occurs when the ideality factor is unity and the capacitance-voltage barrier agrees with the Richardson Plot barrier.

A Proposed Regrowth Mechanism for the Enhancement of Schottky Barrier Height to N-GAAS

1994 ◽  
Vol 337 ◽  
Author(s):  
C-P. Chen ◽  
Y. A. Chang ◽  
T.F. Kuech
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Barrier Height ◽  
Gaas Layer ◽  
Dark Field ◽  
Schottky Barriers ◽  
Semiconductor Interface ◽  
Al Content ◽  
Current Voltage ◽  
High Al Content

ABSTRACTA systematic study of the enhancement of Schottky barriers to n-GaAs diodes has been carried out using the Ni-Al binary system. The diodes, Ni2Al3/n-GaAs, Ni2Al3/Ni/n-GaAs, Ni/Al/Ni/n-GaAs and NiAl/Al/Ni/n-GaAs, have been realized by sputter deposition at a base pressure ∼2xl0-7 Torr. A high Schottky barrier height ranging from 0.95 to 0.98 eV (deduced from current-voltage measurements) was observed for all the annealed contacts except for Ni2Al3/n-GaAs contacts. The enhancement of the Schottky barrier height in all the contacts was attributed to the formation of a high Al content (Al,Ga)As layer at the metal/semiconductor interface. The formation of this (Al,Ga)As layer was explained in terms of a regrowth mechanism. In this mechanism, Ni reacts with GaAs initially at low temperatures, forming NixGaAs. The NixGaAs layer is believed to react with the Ni-Al layer to form the (Al,Ga)As layer when subjected to a high temperature annealing. A (200) dark field XTEM image of the annealed contact was used to demonstrate the existence of this (Al,Ga)As phase.

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