Photoreflectance studies of (Al)Ga- and N-face AlGaN/GaN heterostructures

C. Buchheim; A. T. Winzer; R. Goldhahn; G. Gobsch; O. Ambacher; A. Link; M. Eickhoff; M. Stutzmann

doi:10.1016/j.tsf.2003.10.062

Photoreflectance studies of (Al)Ga- and N-face AlGaN/GaN heterostructures

C. Buchheim, A. T. Winzer, R. Goldhahn, G. Gobsch, O. Ambacher, A. Link, M. Eickhoff, M. Stutzmann

TUM Emeriti of Excellence

Research output: Contribution to journal › Conference article › peer-review

18 Scopus citations

Abstract

Photoreflectance studies were carried out on Al_xGa _1-xN/GaN heterostructures confining high-mobility polarization-induced two-dimensional electron gases. By analyzing the Franz-Keldysh oscillations for samples with (Al)Ga- and N-face polarity, we obtained values for the surface electric field up to F = 380 kVcm^-1 at room temperature. Taking into account spontaneous and piezoelectric polarization, the density of charged surface states and the bare surface potential are estimated. The results unambiguously prove the presence of donor- and acceptor-like surface states for samples with (Al)Ga- and N-face polarity, respectively. A change of the electric field was observed upon the exposure of the surface to a polar liquid, demonstrating the applicability of these structures for chemical sensors.

Original language	English
Pages (from-to)	155-158
Number of pages	4
Journal	Thin Solid Films
Volume	450
Issue number	1
DOIs	https://doi.org/10.1016/j.tsf.2003.10.062
State	Published - 22 Feb 2004
Event	Proceedings of Symposium M on Optical and X-Ray Metrology - Strasbourg, France Duration: 10 Jun 2003 → 13 Jun 2003

Keywords

GaN
Heterostructure
Photoreflectance
Polarization
Surface states

Access to Document

10.1016/j.tsf.2003.10.062

Cite this

@article{016e49aed6054641ba6c4749e8d9199d,

title = "Photoreflectance studies of (Al)Ga- and N-face AlGaN/GaN heterostructures",

abstract = "Photoreflectance studies were carried out on AlxGa 1-xN/GaN heterostructures confining high-mobility polarization-induced two-dimensional electron gases. By analyzing the Franz-Keldysh oscillations for samples with (Al)Ga- and N-face polarity, we obtained values for the surface electric field up to F = 380 kVcm-1 at room temperature. Taking into account spontaneous and piezoelectric polarization, the density of charged surface states and the bare surface potential are estimated. The results unambiguously prove the presence of donor- and acceptor-like surface states for samples with (Al)Ga- and N-face polarity, respectively. A change of the electric field was observed upon the exposure of the surface to a polar liquid, demonstrating the applicability of these structures for chemical sensors.",

keywords = "GaN, Heterostructure, Photoreflectance, Polarization, Surface states",

author = "C. Buchheim and Winzer, {A. T.} and R. Goldhahn and G. Gobsch and O. Ambacher and A. Link and M. Eickhoff and M. Stutzmann",

year = "2004",

month = feb,

day = "22",

doi = "10.1016/j.tsf.2003.10.062",

language = "English",

volume = "450",

pages = "155--158",

journal = "Thin Solid Films",

issn = "0040-6090",

publisher = "Elsevier B.V.",

number = "1",

note = "Proceedings of Symposium M on Optical and X-Ray Metrology ; Conference date: 10-06-2003 Through 13-06-2003",

}

TY - JOUR

T1 - Photoreflectance studies of (Al)Ga- and N-face AlGaN/GaN heterostructures

AU - Buchheim, C.

AU - Winzer, A. T.

AU - Goldhahn, R.

AU - Gobsch, G.

AU - Ambacher, O.

AU - Link, A.

AU - Eickhoff, M.

AU - Stutzmann, M.

PY - 2004/2/22

Y1 - 2004/2/22

N2 - Photoreflectance studies were carried out on AlxGa 1-xN/GaN heterostructures confining high-mobility polarization-induced two-dimensional electron gases. By analyzing the Franz-Keldysh oscillations for samples with (Al)Ga- and N-face polarity, we obtained values for the surface electric field up to F = 380 kVcm-1 at room temperature. Taking into account spontaneous and piezoelectric polarization, the density of charged surface states and the bare surface potential are estimated. The results unambiguously prove the presence of donor- and acceptor-like surface states for samples with (Al)Ga- and N-face polarity, respectively. A change of the electric field was observed upon the exposure of the surface to a polar liquid, demonstrating the applicability of these structures for chemical sensors.

AB - Photoreflectance studies were carried out on AlxGa 1-xN/GaN heterostructures confining high-mobility polarization-induced two-dimensional electron gases. By analyzing the Franz-Keldysh oscillations for samples with (Al)Ga- and N-face polarity, we obtained values for the surface electric field up to F = 380 kVcm-1 at room temperature. Taking into account spontaneous and piezoelectric polarization, the density of charged surface states and the bare surface potential are estimated. The results unambiguously prove the presence of donor- and acceptor-like surface states for samples with (Al)Ga- and N-face polarity, respectively. A change of the electric field was observed upon the exposure of the surface to a polar liquid, demonstrating the applicability of these structures for chemical sensors.

KW - GaN

KW - Heterostructure

KW - Photoreflectance

KW - Polarization

KW - Surface states

UR - http://www.scopus.com/inward/record.url?scp=1142303860&partnerID=8YFLogxK

U2 - 10.1016/j.tsf.2003.10.062

DO - 10.1016/j.tsf.2003.10.062

M3 - Conference article

AN - SCOPUS:1142303860

SN - 0040-6090

VL - 450

SP - 155

EP - 158

JO - Thin Solid Films

JF - Thin Solid Films

IS - 1

T2 - Proceedings of Symposium M on Optical and X-Ray Metrology

Y2 - 10 June 2003 through 13 June 2003

ER -

Photoreflectance studies of (Al)Ga- and N-face AlGaN/GaN heterostructures

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this