First direct observation of EL2-like defect levels in annealed LT-GaAS

N. D. Jäger, A. K. Verma, P. Dreszer, Nathan Newman, Z. Liliental-Weber, M. van Schilfgaarde, E. R. Weber

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Nonstoichiometric arsenic-rich GaAs grown at low temperatures by molecular beam epitaxy (LT-GaAs) has been found to be semi-insulating after high-temperature annealing. The origin of this technologically important conversion is not yet fully understood. In order to study this effect, we performed photocurrent measurements on p-LT GaAs-n diodes in the spectral range between 0.75 and 1.5eV at 8K. The photocurrent spectra revealed the following features which are unique to the EL2 level: photoquenching, characteristic photoionization transitions to conduction band minima and a presence of a broad band due to the effect of auto-ionization from the excited state. Moreover, modeling of the optical excitation process using realistic band structure demonstrates that these features cannot be explained by "internal photoemission" originating from As precipitates, as the "buried Schottky barrier model" predicts. This is the first direct experimental evidence for the existence of EL2-like defect levels and their importance for understanding the optical and electronic properties of annealed LT-GaAs.

Original languageEnglish (US)
Pages (from-to)1499-1502
Number of pages4
JournalJournal of Electronic Materials
Volume22
Issue number12
DOIs
StatePublished - Dec 1993
Externally publishedYes

Fingerprint

Photocurrents
photocurrents
Defects
Photoionization
Photoexcitation
defects
autoionization
Photoemission
Electron transitions
Conduction bands
Arsenic
Excited states
Molecular beam epitaxy
arsenic
Electronic properties
Band structure
excitation
Ionization
photoionization
Precipitates

Keywords

  • Defect
  • EL2 defect
  • internal photoemission
  • low-temperature grown GaAs
  • photocurrent
  • photoquenching

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)
  • Electronic, Optical and Magnetic Materials
  • Materials Science(all)
  • Electrical and Electronic Engineering

Cite this

Jäger, N. D., Verma, A. K., Dreszer, P., Newman, N., Liliental-Weber, Z., van Schilfgaarde, M., & Weber, E. R. (1993). First direct observation of EL2-like defect levels in annealed LT-GaAS. Journal of Electronic Materials, 22(12), 1499-1502. https://doi.org/10.1007/BF02650007

First direct observation of EL2-like defect levels in annealed LT-GaAS. / Jäger, N. D.; Verma, A. K.; Dreszer, P.; Newman, Nathan; Liliental-Weber, Z.; van Schilfgaarde, M.; Weber, E. R.

In: Journal of Electronic Materials, Vol. 22, No. 12, 12.1993, p. 1499-1502.

Research output: Contribution to journalArticle

Jäger, ND, Verma, AK, Dreszer, P, Newman, N, Liliental-Weber, Z, van Schilfgaarde, M & Weber, ER 1993, 'First direct observation of EL2-like defect levels in annealed LT-GaAS', Journal of Electronic Materials, vol. 22, no. 12, pp. 1499-1502. https://doi.org/10.1007/BF02650007
Jäger ND, Verma AK, Dreszer P, Newman N, Liliental-Weber Z, van Schilfgaarde M et al. First direct observation of EL2-like defect levels in annealed LT-GaAS. Journal of Electronic Materials. 1993 Dec;22(12):1499-1502. https://doi.org/10.1007/BF02650007
Jäger, N. D. ; Verma, A. K. ; Dreszer, P. ; Newman, Nathan ; Liliental-Weber, Z. ; van Schilfgaarde, M. ; Weber, E. R. / First direct observation of EL2-like defect levels in annealed LT-GaAS. In: Journal of Electronic Materials. 1993 ; Vol. 22, No. 12. pp. 1499-1502.
@article{fe0538b6b7fc4bbf8af81ca9de79e53b,
title = "First direct observation of EL2-like defect levels in annealed LT-GaAS",
abstract = "Nonstoichiometric arsenic-rich GaAs grown at low temperatures by molecular beam epitaxy (LT-GaAs) has been found to be semi-insulating after high-temperature annealing. The origin of this technologically important conversion is not yet fully understood. In order to study this effect, we performed photocurrent measurements on p-LT GaAs-n diodes in the spectral range between 0.75 and 1.5eV at 8K. The photocurrent spectra revealed the following features which are unique to the EL2 level: photoquenching, characteristic photoionization transitions to conduction band minima and a presence of a broad band due to the effect of auto-ionization from the excited state. Moreover, modeling of the optical excitation process using realistic band structure demonstrates that these features cannot be explained by {"}internal photoemission{"} originating from As precipitates, as the {"}buried Schottky barrier model{"} predicts. This is the first direct experimental evidence for the existence of EL2-like defect levels and their importance for understanding the optical and electronic properties of annealed LT-GaAs.",
keywords = "Defect, EL2 defect, internal photoemission, low-temperature grown GaAs, photocurrent, photoquenching",
author = "J{\"a}ger, {N. D.} and Verma, {A. K.} and P. Dreszer and Nathan Newman and Z. Liliental-Weber and {van Schilfgaarde}, M. and Weber, {E. R.}",
year = "1993",
month = "12",
doi = "10.1007/BF02650007",
language = "English (US)",
volume = "22",
pages = "1499--1502",
journal = "Journal of Electronic Materials",
issn = "0361-5235",
publisher = "Springer New York",
number = "12",

}

TY - JOUR

T1 - First direct observation of EL2-like defect levels in annealed LT-GaAS

AU - Jäger, N. D.

AU - Verma, A. K.

AU - Dreszer, P.

AU - Newman, Nathan

AU - Liliental-Weber, Z.

AU - van Schilfgaarde, M.

AU - Weber, E. R.

PY - 1993/12

Y1 - 1993/12

N2 - Nonstoichiometric arsenic-rich GaAs grown at low temperatures by molecular beam epitaxy (LT-GaAs) has been found to be semi-insulating after high-temperature annealing. The origin of this technologically important conversion is not yet fully understood. In order to study this effect, we performed photocurrent measurements on p-LT GaAs-n diodes in the spectral range between 0.75 and 1.5eV at 8K. The photocurrent spectra revealed the following features which are unique to the EL2 level: photoquenching, characteristic photoionization transitions to conduction band minima and a presence of a broad band due to the effect of auto-ionization from the excited state. Moreover, modeling of the optical excitation process using realistic band structure demonstrates that these features cannot be explained by "internal photoemission" originating from As precipitates, as the "buried Schottky barrier model" predicts. This is the first direct experimental evidence for the existence of EL2-like defect levels and their importance for understanding the optical and electronic properties of annealed LT-GaAs.

AB - Nonstoichiometric arsenic-rich GaAs grown at low temperatures by molecular beam epitaxy (LT-GaAs) has been found to be semi-insulating after high-temperature annealing. The origin of this technologically important conversion is not yet fully understood. In order to study this effect, we performed photocurrent measurements on p-LT GaAs-n diodes in the spectral range between 0.75 and 1.5eV at 8K. The photocurrent spectra revealed the following features which are unique to the EL2 level: photoquenching, characteristic photoionization transitions to conduction band minima and a presence of a broad band due to the effect of auto-ionization from the excited state. Moreover, modeling of the optical excitation process using realistic band structure demonstrates that these features cannot be explained by "internal photoemission" originating from As precipitates, as the "buried Schottky barrier model" predicts. This is the first direct experimental evidence for the existence of EL2-like defect levels and their importance for understanding the optical and electronic properties of annealed LT-GaAs.

KW - Defect

KW - EL2 defect

KW - internal photoemission

KW - low-temperature grown GaAs

KW - photocurrent

KW - photoquenching

UR - http://www.scopus.com/inward/record.url?scp=0027811805&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027811805&partnerID=8YFLogxK

U2 - 10.1007/BF02650007

DO - 10.1007/BF02650007

M3 - Article

VL - 22

SP - 1499

EP - 1502

JO - Journal of Electronic Materials

JF - Journal of Electronic Materials

SN - 0361-5235

IS - 12

ER -