Theoretical Models of Schottky Barriers

1981 ◽  
Vol 10 ◽  
Author(s):  
M. Schluter
Keyword(s):  
Theoretical Models ◽  
Interface States ◽  
Schottky Barriers ◽  
Quantum Mechanical ◽  
Barrier Heights

ABSTRACTA review is presented in which existing theories of the formation of Schottky barriers are analyzed. The list includes macroscopic dielectric approaches and various microscopic quantum mechanical treatments. The central role of interface states and their different physical origins are assessed. Simple concepts, able to predict general trends in barrier heights, are examined along with detailed microscopic theories applied to individual contacts.

The Role of Distress Disclosure Tendencies in the Experience and Expression of Laboratory-Induced Sadness

2017 ◽  
Vol 38 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Jeffrey H. Kahn ◽  
Daniel W. Cox ◽  
A. Myfanwy Bakker ◽  
Julia I. O’Loughlin ◽  
Agnieszka M. Kotlarczyk
Keyword(s):  
Individual Differences ◽  
Emotional Reactivity ◽  
Subjective Experience ◽  
Negative Emotion ◽  
Theoretical Models ◽  
Laboratory Research ◽  
Emotion Words ◽  
Distress Disclosure ◽  
Computerized Text Analysis

Abstract. The benefits of talking with others about unpleasant emotions have been thoroughly investigated, but individual differences in distress disclosure tendencies have not been adequately integrated within theoretical models of emotion. The purpose of this laboratory research was to determine whether distress disclosure tendencies stem from differences in emotional reactivity or differences in emotion regulation. After completing measures of distress disclosure tendencies, social desirability, and positive and negative affect, 84 participants (74% women) were video recorded while viewing a sadness-inducing film clip. Participants completed post-film measures of affect and were then interviewed about their reactions to the film; these interviews were audio recorded for later coding and computerized text analysis. Distress disclosure tendencies were not predictive of the subjective experience of emotion, but they were positively related to facial expressions of sadness and happiness. Distress disclosure tendencies also predicted judges’ ratings of the verbal disclosure of emotion during the interview, but self-reported disclosure and use of positive and negative emotion words were not associated with distress disclosure tendencies. The authors present implications of this research for integrating individual differences in distress disclosure with models of emotion.

Exploring the role of identity fusion and group identification in predicting parochialism amongst Indonesian Islamic groups

2019 ◽  
Author(s):  
Christopher Michael Kavanagh ◽  
Susilo Wibisono ◽  
Rohan Kapitány ◽  
Whinda Yustisia ◽  
Idhamsyah Eka Putra ◽  
...  
Keyword(s):  
Group Identification ◽  
Control Sample ◽  
Theoretical Models ◽  
Religious Groups ◽  
Diverse Range ◽  
Beliefs And Practices ◽  
Identity Fusion ◽  
Beliefs And Practice ◽  
Fusion Theory

Indonesia is the most populous Islamic country and as such is host to a diverse range of Islamic beliefs and practices. Here we examine how the diversity of beliefs and practices among Indonesian Muslims relates to group bonding and parochialism. In particular, we examine the predictive power of two distinct types of group alignment, group identification and identity fusion, among individuals from three Sunni politico-religious groups - a fundamentalist group (PKS), a moderate group (NU), and a control sample of politically unaffiliated citizens. Fundamentalists were more fused to targets than moderates or citizens, but contrary to fusion theory, we found across all groups, that group identification (not fusion) better predicted parochialism, including willingness to carry out extreme pro-group actions. We discuss how religious beliefs and practice impact parochial attitudes, as well as the implications for theoretical models linking fusion to extreme behaviour.

scholarly journals Quantum postulate vs. quantum nonlocality: on the role of the Planck constant in Bell’s argument

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Andrei Khrennikov
Keyword(s):  
Quantum Nonlocality ◽  
Quantum Mechanical ◽  
Quantum Foundations ◽  
Planck Constant ◽  
Variable Model ◽  
Basic Principles ◽  
Fundamental Feature ◽  
Hidden Variable ◽  
Bell Model

AbstractWe present a quantum mechanical (QM) analysis of Bell’s approach to quantum foundations based on his hidden-variable model. We claim and try to justify that the Bell model contradicts to the Heinsenberg’s uncertainty and Bohr’s complementarity principles. The aim of this note is to point to the physical seed of the aforementioned principles. This is the Bohr’s quantum postulate: the existence of indivisible quantum of action given by the Planck constant h. By contradicting these basic principles of QM, Bell’s model implies rejection of this postulate as well. Thus, this hidden-variable model contradicts not only the QM-formalism, but also the fundamental feature of the quantum world discovered by Planck.

scholarly journals Theoretical Study on the Photo-Oxidation and Photoreduction of an Azetidine Derivative as a Model of DNA Repair

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2911
Author(s):  
Miriam Navarrete-Miguel ◽  
Antonio Francés-Monerris ◽  
Miguel A. Miranda ◽  
Virginie Lhiaubet-Vallet ◽  
Daniel Roca-Sanjuán
Keyword(s):  
Electron Transfer ◽  
Energy Barrier ◽  
Ring Opening ◽  
Dna Lesions ◽  
Barrier Heights ◽  
Dna Lesion ◽  
Electron Reduction ◽  
The Stability ◽  
Electron Transfer Processes

Photocycloreversion plays a central role in the study of the repair of DNA lesions, reverting them into the original pyrimidine nucleobases. Particularly, among the proposed mechanisms for the repair of DNA (6-4) photoproducts by photolyases, it has been suggested that it takes place through an intermediate characterized by a four-membered heterocyclic oxetane or azetidine ring, whose opening requires the reduction of the fused nucleobases. The specific role of this electron transfer step and its impact on the ring opening energetics remain to be understood. These processes are studied herein by means of quantum-chemical calculations on the two azetidine stereoisomers obtained from photocycloaddition between 6-azauracil and cyclohexene. First, we analyze the efficiency of the electron-transfer processes by computing the redox properties of the azetidine isomers as well as those of a series of aromatic photosensitizers acting as photoreductants and photo-oxidants. We find certain stereodifferentiation favoring oxidation of the cis-isomer, in agreement with previous experimental data. Second, we determine the reaction profiles of the ring-opening mechanism of the cationic, neutral, and anionic systems and assess their feasibility based on their energy barrier heights and the stability of the reactants and products. Results show that oxidation largely decreases the ring-opening energy barrier for both stereoisomers, even though the process is forecast as too slow to be competitive. Conversely, one-electron reduction dramatically facilitates the ring opening of the azetidine heterocycle. Considering the overall quantum-chemistry findings, N,N-dimethylaniline is proposed as an efficient photosensitizer to trigger the photoinduced cycloreversion of the DNA lesion model.

Quantum mechanical tunnelling: the missing term to achieve sub-kJ mol−1 barrier heights

2021 ◽  
Author(s):  
Sebastian Kozuch ◽  
Tim Schleif ◽  
Amir Karton
Keyword(s):  
Barrier Height ◽  
Quantum Mechanical ◽  
Effective Barrier Height ◽  
Quantum Tunnelling ◽  
Barrier Heights ◽  
Effective Barrier

Quantum tunnelling can lower the effective barrier height, creating a discrepancy between experiment and theory.

Role of amphoteric defects in the formation of metal/GaAs Schottky barriers

1991 ◽  
Vol 58 (24) ◽  
pp. 2785-2787 ◽  
Author(s):  
T. Zhang ◽  
T. W. Sigmon
Keyword(s):  
Schottky Barriers

scholarly journals The role of quantum confinement in the formation of Schottky barriers in Pb–Si interfaces

2015 ◽  
Vol 217 ◽  
pp. 43-46 ◽  
Author(s):  
Tzu-Liang Chan ◽  
Jaime Souto-Casares ◽  
James R. Chelikowsky ◽  
Kai-Ming Ho ◽  
Cai-Zhuang Wang ◽  
...  
Keyword(s):  
Quantum Confinement ◽  
Schottky Barriers

Nanoscale Deep Level Defect Correlation with Schottky Barriers in 4H-SiC/Metal Diodes

2006 ◽  
Vol 527-529 ◽  
pp. 907-910
Author(s):  
Sergey P. Tumakha ◽  
L.M. Porter ◽  
D.J. Ewing ◽  
Qamar-ul Wahab ◽  
X.Y. Ma ◽  
...  
Keyword(s):  
Surface Defect ◽  
Deep Level ◽  
Polarized Light ◽  
Schottky Barriers ◽  
Double Barrier ◽  
Barrier Heights ◽  
Current Voltage ◽  
Cathodoluminescence Spectroscopy ◽  
Morphological Defects ◽  
Additional Defect

We have used depth-resolved cathodoluminescence spectroscopy (DRCLS) to correlate subsurface deep level emissions and double barrier current-voltage (I-V) characteristics across an array of Ni/4H-SiC diodes on the same epitaxial wafer. These results demonstrate not only a correspondence between these optical features and measured barrier heights, but they also suggest that such states may limit the range of SB heights in general. DRCLS of near-ideal diodes show a broad 2.45 eV emission at common to all diode areas and associated with either impurities or inclusions. Strongly non-ideal diodes exhibit additional defect emissions at 2.2 and 2.65 eV. On the other hand, there is no correlation between the appearance of morphological defects observed by polarized light microscopy or X-ray topography and the presence of double barrier characteristics. The DRCLS observations of defect level transitions that correlate with non-ideal Schottky barriers suggest that these sub-surface defect features can be used to predict Schottky barrier behavior.

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