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Title: Correct implementation of polarization constants in wurtzite materials and impact on III-nitrides

Abstract

Here, accurate values for polarization discontinuities between pyroelectric materials are critical for understanding and designing the electronic properties of heterostructures. For wurtzite materials, the zincblende structure has been used in the literature as a reference to determine the effective spontaneous polarization constants. We show that, because the zincblende structure has a nonzero formal polarization, this method results in a spurious contribution to the spontaneous polarization differences between materials. In addition, we address the correct choice of "improper" versus "proper" piezoelectric constants. For the technologically important III-nitride materials GaN, AlN, and InN, we determine polarization discontinuities using a consistent reference based on the layered hexagonal structure and the correct choice of piezoelectric constants, and discuss the results in light of available experimental data.

Authors:
 [1];  [2];  [2];  [3]
  1. Univ. of California, Santa Barbara, CA (United States). Materials Dept.; Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy
  2. Univ. of California, Santa Barbara, CA (United States). Materials Dept.
  3. Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy
Publication Date:
Research Org.:
Univ. of California, Santa Barbara, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1258317
Grant/Contract Number:
SC0010689; AC02-05CH11231
Resource Type:
Journal Article: Published Article
Journal Name:
Physical Review. X
Additional Journal Information:
Journal Volume: 6; Journal Issue: 2; Journal ID: ISSN 2160-3308
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; aluminum nitride; gallium nitride; quantum-wells; alxga1-xn/gan heterostructures; piezoelectric coefficients; algan/gan heterostructures; electron-gas; thin-films; transistors; fields

Citation Formats

Dreyer, Cyrus E., Janotti, Anderson, Van de Walle, Chris G., and Vanderbilt, David. Correct implementation of polarization constants in wurtzite materials and impact on III-nitrides. United States: N. p., 2016. Web. doi:10.1103/PhysRevX.6.021038.
Dreyer, Cyrus E., Janotti, Anderson, Van de Walle, Chris G., & Vanderbilt, David. Correct implementation of polarization constants in wurtzite materials and impact on III-nitrides. United States. doi:10.1103/PhysRevX.6.021038.
Dreyer, Cyrus E., Janotti, Anderson, Van de Walle, Chris G., and Vanderbilt, David. 2016. "Correct implementation of polarization constants in wurtzite materials and impact on III-nitrides". United States. doi:10.1103/PhysRevX.6.021038.
@article{osti_1258317,
title = {Correct implementation of polarization constants in wurtzite materials and impact on III-nitrides},
author = {Dreyer, Cyrus E. and Janotti, Anderson and Van de Walle, Chris G. and Vanderbilt, David},
abstractNote = {Here, accurate values for polarization discontinuities between pyroelectric materials are critical for understanding and designing the electronic properties of heterostructures. For wurtzite materials, the zincblende structure has been used in the literature as a reference to determine the effective spontaneous polarization constants. We show that, because the zincblende structure has a nonzero formal polarization, this method results in a spurious contribution to the spontaneous polarization differences between materials. In addition, we address the correct choice of "improper" versus "proper" piezoelectric constants. For the technologically important III-nitride materials GaN, AlN, and InN, we determine polarization discontinuities using a consistent reference based on the layered hexagonal structure and the correct choice of piezoelectric constants, and discuss the results in light of available experimental data.},
doi = {10.1103/PhysRevX.6.021038},
journal = {Physical Review. X},
number = 2,
volume = 6,
place = {United States},
year = 2016,
month = 6
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevX.6.021038

Citation Metrics:
Cited by: 2works
Citation information provided by
Web of Science

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  • Here, accurate values for polarization discontinuities between pyroelectric materials are critical for understanding and designing the electronic properties of heterostructures. For wurtzite materials, the zincblende structure has been used in the literature as a reference to determine the effective spontaneous polarization constants. We show that, because the zincblende structure has a nonzero formal polarization, this method results in a spurious contribution to the spontaneous polarization differences between materials. In addition, we address the correct choice of "improper" versus "proper" piezoelectric constants. For the technologically important III-nitride materials GaN, AlN, and InN, we determine polarization discontinuities using a consistent reference basedmore » on the layered hexagonal structure and the correct choice of piezoelectric constants, and discuss the results in light of available experimental data.« less
  • We report first-principle density functional calculations of the spontaneous polarization, piezoelectric stress constants, and elastic constants for the III–V wurtzite structure semiconductors InAs and InP. Using the density functional theory implemented in the VASP code, we obtain polarization values–0.011 and–0.013 C/m{sup 2}, and piezoelectric constants e{sub 33} (e{sub 31}) equal to 0.091 (–0.026) and 0.012 (–0.081) C/m{sup 2} for structurally relaxed InP and InAs respectively. These values are consistently smaller than those of nitrides. Therefore, we predict a smaller built-in electric field in such structures.
  • The spontaneous polarization, dynamical Born charges, and piezoelectric constants of the III-V nitrides AlN, GaN, and InN are studied {ital ab initio} using the Berry-phase approach to polarization in solids. The piezoelectric constants are found to be up to ten times larger than in conventional III-V and II-VI semiconductor compounds, and comparable to those of ZnO. Further properties at variance with those of conventional III-V compounds are the sign of the piezoelectric constants (positive as in II-VI compounds) and the very large spontaneous polarization. {copyright} {ital 1997} {ital The American Physical Society}
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