Role Of Hydrogen And Hydrogen Complexes In Doping Of Gan

MRS Proceedings ◽

10.1557/proc-423-619 ◽

1996 ◽

Vol 423 ◽

Cited By ~ 8

Author(s):

Jörg Neugebauer ◽

Chris G. Van de wallei

Keyword(s):

Electronic Structure ◽

First Principles ◽

State Of The Art ◽

Growth Conditions ◽

Fundamental Difference ◽

First Principles Calculations ◽

Native Defects ◽

In Doping ◽

And Migration

AbstractWe have calculated electronic structure, energetics and migration for hydrogen and hydrogen complexes in GaN employing state-of-the-art first-principles calculations. Using these results in combination with previous detailed investigations about native defects we have calculated the concentration of hydrogen and dopants for different growth conditions. Our results reveal a fundamental difference in the behavior of hydrogen in p-type and n-type material. In particular, we explain why hydrogen has little effect on donor impurities and why H concentrations are low in n-type GaN. We discuss why hydrogen is beneficial for acceptor incorporation in GaN, and identify the limitations of this process.

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Theory of Defects in Wide-Band-Gap Semiconductors

MRS Proceedings ◽

10.1557/proc-378-467 ◽

1995 ◽

Vol 378 ◽

Cited By ~ 1

Author(s):

Chris G Van de Walle ◽

Jörg Neugebauer

Keyword(s):

Band Gap ◽

First Principles ◽

State Of The Art ◽

Wide Band ◽

First Principles Calculations ◽

Wide Band Gap ◽

Native Defects ◽

In Doping ◽

Wide Band Gap Semiconductors

AbstractWe discuss the application of state-of-the-art first-principles calculations to the problem of defects, impurities, and doping levels in semiconductors. Since doping problems are of particular relevance in wide-band-gap materials, we focus here on studies of ZnSe and GaN. For ZnSe, we discuss our latest insights in the influence of compensation and dopant solubility on the experimentally observed limitation of the free carrier concentration in p-type ZnSe. For GaN, we focus on the role of native defects in doping or compensation of the material, with particular emphasis on the n-type conductivity of as-grown GaN.

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Theory of Point Defects and Complexes in GaN

MRS Proceedings ◽

10.1557/proc-395-645 ◽

1995 ◽

Vol 395 ◽

Cited By ~ 59

Author(s):

Jörg Neugebauer ◽

Chris G. Van de Walle

Keyword(s):

First Principles ◽

State Of The Art ◽

Growth Parameters ◽

Free Carrier ◽

First Principles Calculations ◽

Acceptor Doping ◽

Native Defects ◽

Chemical Potentials ◽

Insight Into

ABSTRACTWe have studied the electronic and energetic properties of native defects, impurities and complexes in GaN applying state-of-the-art first-principles calculations. An analysis of the numerical results gives direct insight into defect concentrations and impurity solubility with respect to growth parameters (temperature, chemical potentials) and into the mechanisms limiting the doping levels in GaN. We show how compensation and passivation by native defects or impurities, solubility issues, and incorporation of dopants on other sites influence the acceptor doping levels. The role of hydrogen in enhancing the p-type doping is explained in detail. We also discuss the mechanisms responsible for the experimentally observed limitation of the free-carrier concentration in p-type GaN.

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Electronic Structure and Hydrogen Desorption in NaAlH4

MRS Proceedings ◽

10.1557/proc-837-n2.5 ◽

2004 ◽

Vol 837 ◽

Cited By ~ 1

Author(s):

S. Li ◽

P. Jena ◽

C. M. Araujo ◽

R. Ahuja

Keyword(s):

Electronic Structure ◽

First Principles ◽

Density Functional ◽

Metal Hydrides ◽

Hydrogen Desorption ◽

Light Metal ◽

First Principles Calculations ◽

Functional Theory ◽

Design And Synthesis

ABSTRACTFirst principles calculations based on gradient corrected density functional theory are carried out to understand the electronic structure and mechanisms responsible for desorption of hydrogen from Ti doped and vacancy containing sodium-alanate (NaAlH4). The energy necessary to remove a hydrogen atom from Ti doped NaAlH4 is significantly smaller than that from pristine NaAlH4 irrespective of whether Ti substitutes the Na or the Al site. However, the presence of Na and Al vacancies is shown to play an even more important role: The removal of hydrogen associated with both Na and Al vacancies is found to be exothermic. It is suggested that this role of vacancies can be exploited in the design and synthesis of complex light metal hydrides suitable for hydrogen storage.

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The stability, electronic structure, and optical absorption of boron-nitride diamondoids predicted with first-principles calculations

Physical Chemistry Chemical Physics ◽

10.1039/c8cp02377h ◽

2018 ◽

Vol 20 (28) ◽

pp. 19188-19194 ◽

Cited By ~ 3

Author(s):

Weiwei Gao ◽

Linda Hung ◽

Serdar Ogut ◽

James R. Chelikowsky

Keyword(s):

Optical Properties ◽

Electronic Structure ◽

Boron Nitride ◽

Optical Absorption ◽

Computational Methods ◽

First Principles ◽

State Of The Art ◽

First Principles Calculations ◽

The Stability

The stability, electronic structure, and optical properties of six boron-nitride diamondoids are systematically studied with state-of-the-art computational methods and compared with diamondoids.

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