Electrical and optical properties of bulk GaN substrates studied by Kelvin probe and photoluminescence

Joy Dorene McNamara, M. A. Foussekis, A. A. Baski, X. Li, V. Avrutin, H. Morkoç, J. H. Leach, T. Paskova, K. Udwary, E. Preble, M. A. Reshchikov

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

We have investigated the N- and Ga-polar faces of bulk GaN substrates with photoluminescence (PL) and the surface photovoltage (SPV) technique using a Kelvin probe attached to an optical cryostat. Experiments were conducted in vacuum. Some of the surfaces were mechanically polished (MP), while others were epi-ready after a chemical-mechanical polish (CMP). From the SPV measurements, the band bending in a sample having both surfaces treated with the CMP method was calculated to be about 0.83 and 0.70 eV for the Ga- and N-polar surfaces, respectively. The restoration of the SPV after ceasing the UV illumination showed that the SPV from CMP-treated surfaces behaved as predicted by a thermionic model, whereas the SPV from MP-treated surfaces restored with a much faster-than-predicted rate. This result can be interpreted by the hopping of charge carriers in the highly-defective near-surface layer of the MP-treated samples. Remarkably, removing the top 700 nm defective layer by dry etching restored the quality of the electrical and optical properties of GaN.

Original languageEnglish (US)
Pages (from-to)536-539
Number of pages4
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Volume10
Issue number3
DOIs
StatePublished - Mar 1 2013

Fingerprint

electrical properties
photoluminescence
optical properties
probes
photovoltages
thermionics
cryostats
restoration
charge carriers
surface layers
illumination
etching
vacuum

Keywords

  • GaN
  • Kelvin probe
  • Photoluminescence
  • Surface

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Electrical and optical properties of bulk GaN substrates studied by Kelvin probe and photoluminescence. / McNamara, Joy Dorene; Foussekis, M. A.; Baski, A. A.; Li, X.; Avrutin, V.; Morkoç, H.; Leach, J. H.; Paskova, T.; Udwary, K.; Preble, E.; Reshchikov, M. A.

In: Physica Status Solidi (C) Current Topics in Solid State Physics, Vol. 10, No. 3, 01.03.2013, p. 536-539.

Research output: Contribution to journalArticle

McNamara, JD, Foussekis, MA, Baski, AA, Li, X, Avrutin, V, Morkoç, H, Leach, JH, Paskova, T, Udwary, K, Preble, E & Reshchikov, MA 2013, 'Electrical and optical properties of bulk GaN substrates studied by Kelvin probe and photoluminescence', Physica Status Solidi (C) Current Topics in Solid State Physics, vol. 10, no. 3, pp. 536-539. https://doi.org/10.1002/pssc.201200662
McNamara, Joy Dorene ; Foussekis, M. A. ; Baski, A. A. ; Li, X. ; Avrutin, V. ; Morkoç, H. ; Leach, J. H. ; Paskova, T. ; Udwary, K. ; Preble, E. ; Reshchikov, M. A. / Electrical and optical properties of bulk GaN substrates studied by Kelvin probe and photoluminescence. In: Physica Status Solidi (C) Current Topics in Solid State Physics. 2013 ; Vol. 10, No. 3. pp. 536-539.
@article{bc7448707c014754bef7a7193ee71334,
title = "Electrical and optical properties of bulk GaN substrates studied by Kelvin probe and photoluminescence",
abstract = "We have investigated the N- and Ga-polar faces of bulk GaN substrates with photoluminescence (PL) and the surface photovoltage (SPV) technique using a Kelvin probe attached to an optical cryostat. Experiments were conducted in vacuum. Some of the surfaces were mechanically polished (MP), while others were epi-ready after a chemical-mechanical polish (CMP). From the SPV measurements, the band bending in a sample having both surfaces treated with the CMP method was calculated to be about 0.83 and 0.70 eV for the Ga- and N-polar surfaces, respectively. The restoration of the SPV after ceasing the UV illumination showed that the SPV from CMP-treated surfaces behaved as predicted by a thermionic model, whereas the SPV from MP-treated surfaces restored with a much faster-than-predicted rate. This result can be interpreted by the hopping of charge carriers in the highly-defective near-surface layer of the MP-treated samples. Remarkably, removing the top 700 nm defective layer by dry etching restored the quality of the electrical and optical properties of GaN.",
keywords = "GaN, Kelvin probe, Photoluminescence, Surface",
author = "McNamara, {Joy Dorene} and Foussekis, {M. A.} and Baski, {A. A.} and X. Li and V. Avrutin and H. Morko{\cc} and Leach, {J. H.} and T. Paskova and K. Udwary and E. Preble and Reshchikov, {M. A.}",
year = "2013",
month = "3",
day = "1",
doi = "10.1002/pssc.201200662",
language = "English (US)",
volume = "10",
pages = "536--539",
journal = "Physica Status Solidi (C) Current Topics in Solid State Physics",
issn = "1862-6351",
publisher = "Wiley-VCH Verlag",
number = "3",

}

TY - JOUR

T1 - Electrical and optical properties of bulk GaN substrates studied by Kelvin probe and photoluminescence

AU - McNamara, Joy Dorene

AU - Foussekis, M. A.

AU - Baski, A. A.

AU - Li, X.

AU - Avrutin, V.

AU - Morkoç, H.

AU - Leach, J. H.

AU - Paskova, T.

AU - Udwary, K.

AU - Preble, E.

AU - Reshchikov, M. A.

PY - 2013/3/1

Y1 - 2013/3/1

N2 - We have investigated the N- and Ga-polar faces of bulk GaN substrates with photoluminescence (PL) and the surface photovoltage (SPV) technique using a Kelvin probe attached to an optical cryostat. Experiments were conducted in vacuum. Some of the surfaces were mechanically polished (MP), while others were epi-ready after a chemical-mechanical polish (CMP). From the SPV measurements, the band bending in a sample having both surfaces treated with the CMP method was calculated to be about 0.83 and 0.70 eV for the Ga- and N-polar surfaces, respectively. The restoration of the SPV after ceasing the UV illumination showed that the SPV from CMP-treated surfaces behaved as predicted by a thermionic model, whereas the SPV from MP-treated surfaces restored with a much faster-than-predicted rate. This result can be interpreted by the hopping of charge carriers in the highly-defective near-surface layer of the MP-treated samples. Remarkably, removing the top 700 nm defective layer by dry etching restored the quality of the electrical and optical properties of GaN.

AB - We have investigated the N- and Ga-polar faces of bulk GaN substrates with photoluminescence (PL) and the surface photovoltage (SPV) technique using a Kelvin probe attached to an optical cryostat. Experiments were conducted in vacuum. Some of the surfaces were mechanically polished (MP), while others were epi-ready after a chemical-mechanical polish (CMP). From the SPV measurements, the band bending in a sample having both surfaces treated with the CMP method was calculated to be about 0.83 and 0.70 eV for the Ga- and N-polar surfaces, respectively. The restoration of the SPV after ceasing the UV illumination showed that the SPV from CMP-treated surfaces behaved as predicted by a thermionic model, whereas the SPV from MP-treated surfaces restored with a much faster-than-predicted rate. This result can be interpreted by the hopping of charge carriers in the highly-defective near-surface layer of the MP-treated samples. Remarkably, removing the top 700 nm defective layer by dry etching restored the quality of the electrical and optical properties of GaN.

KW - GaN

KW - Kelvin probe

KW - Photoluminescence

KW - Surface

UR - http://www.scopus.com/inward/record.url?scp=84874984650&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84874984650&partnerID=8YFLogxK

U2 - 10.1002/pssc.201200662

DO - 10.1002/pssc.201200662

M3 - Article

VL - 10

SP - 536

EP - 539

JO - Physica Status Solidi (C) Current Topics in Solid State Physics

JF - Physica Status Solidi (C) Current Topics in Solid State Physics

SN - 1862-6351

IS - 3

ER -