A Theoretical Study of p-Type Doping of ZnO: Problems and Solutions

ABSTRACTWe present results of a comprehensive set of first-principles total-energy calculations of native and impurity-defect complexes in ZnO and use these results to elucidate the problems that occur in efforts to achieve p-type doping. The analysis naturally leads to new approaches that are likely to overcome the difficulties. The results provide detailed explanations of recent puzzling observations made in attempts to produce p-type ZnO.

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Theory of Hydrogen Reactions in Silicon

MRS Proceedings ◽

10.1557/proc-104-253 ◽

1987 ◽

Vol 104 ◽

Author(s):

Chris G. Van De Walle ◽

Y. Bar-Yam ◽

S. T. Pantelides

Keyword(s):

Fermi Level ◽

Total Energy ◽

First Principles ◽

Type Material ◽

Energy Calculations ◽

And Migration ◽

The Stability ◽

Hydrogen Reactions ◽

Energy Surfaces ◽

P Type

ABSTRACTWe report first-principles total-energy calculations for H atoms in a Si lattice. Our results for single H atoms are presented in the form of total-energy surfaces, providing immediate insight in stable positions and migration paths. We examine the stability of different charge states (H+, H0, H−) as a function of Fermi-level position, and its impli-cations for H diffusion in p-type vs. n-type material. The results are used to scrutinize and supplement existing understanding of experimental observations. We also study the co-operative interactions of several H atoms, and propose a novel mechanism for H-induced damage.

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Defect Complexes and Non-Equilibrium Processes Underlying the P-Type Doping of GaN

MRS Proceedings ◽

10.1557/proc-537-g5.3 ◽

1998 ◽

Vol 537 ◽

Author(s):

Fernando A. Reboredo ◽

Sokrates T. Pantelides

Keyword(s):

High Temperature ◽

Experimental Evidence ◽

First Principles ◽

Final Anneal ◽

First Principles Calculations ◽

Defect Complexes ◽

Equilibrium Processes ◽

Open Questions ◽

High Temperature Anneal ◽

P Type

AbstractIt is well known that hydrogen plays a key role in p-type doping of GaN. It is believed that H passivates substitutional Mg during growth by forming a Mgs-N-Hi complex; in subsequent annealing, H is removed, resulting in p-type doping. Several open questions have remained, however, such as experimental evidence for other complexes involving Mg and H and difficulties in accounting for the relatively high-temperature anneal needed to remove H. We present first principles calculations in terms of which we show that the doping process is in fact significantly more complex. In particular, interstitial Mg plays a major role in limiting p-type doping. Overall, several substitutional/interstitial complexes form and can bind H, with vibrational frequencies that account for hitherto unidentified observed lines. We predict that these defects, which limit doping efficiency, can be eliminated by annealing in an atmosphere of H and N prior to the final anneal that removes H.

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Atomic configurations and energetics of vacancies in hexagonal boron nitride: First-principles total-energy calculations

Physical Review B ◽

10.1103/physrevb.80.161404 ◽

2009 ◽

Vol 80 (16) ◽

Cited By ~ 59

Author(s):

Susumu Okada

Keyword(s):

Boron Nitride ◽

Total Energy ◽

First Principles ◽

Hexagonal Boron Nitride ◽

Energy Calculations

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Phase Stability of the Sigma Phase in Fe-Cr Based Alloys

MRS Proceedings ◽

10.1557/proc-408-369 ◽

1995 ◽

Vol 408 ◽

Author(s):

Marcel Il. F ◽

Sluiter. Koivan Esfurjani ◽

Yoshiyuki Kawazoe

Keyword(s):

Total Energy ◽

Phase Stability ◽

First Principles ◽

Finite Temperature ◽

Sigma Phase ◽

Complex Structure ◽

Unit Cell ◽

Energy Calculations ◽

Cluster Variation ◽

The Stability

AbstractThe FeCr sigma phase is a good example of a complex structure: it. has 30 atoms in the unit cell and 5 inequivalent lattice sites, and it belongs to the class of tetrahedrally close packed structures, also known as Frank-Kaspar structures. So far. such structures have riot been treated within a first-principles statistical thermodynamics framework. It will be shown that dtlme to advances in algorithms and hardware important features of the phase stability of complex phases can be computed. The factors which affect the stability of the sigma phase have been studied using carefully selected supercells for electronic total energy calculations. cluster variation calc:ulations in the tet.rahedron approximation were performed to evaluate the effect of partial disorder and of finite temperature. The preferred occupancy of the 5 lattice sites has been investigated and is compared with experimental determinations.

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