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Enhancement of 2DEG effective mass in AlN/Al0.78Ga0.22N high electron mobility transistor structure determined by THz optical Hall effect

Kühne, Philipp ; Armakavicius, Nerijus ; Papamichail, Alexis ; Tran, Dat Q. ; Stanishev, Vallery ; Schubert, Mathias ; Paskov, Plamen P. and Darakchieva, Vanya LU (2022) In Applied Physics Letters 120(25).
Abstract

We report on the free charge carrier properties of a two-dimensional electron gas (2DEG) in an AlN/AlxGa1-xN high electron mobility transistor structure with a high aluminum content (x = 0.78). The 2DEG sheet density N s = (7.3 ± 0.7) × 10 12 cm-2, sheet mobility μ s = (270 ± 40) cm2/(Vs), sheet resistance R s = (3200 ± 500) ω / □, and effective mass m eff = (0.63 ± 0.04) m 0 at low temperatures (T = 5 K) are determined by terahertz (THz) optical Hall effect measurements. The experimental 2DEG mobility in the channel is found within the expected range, and the sheet carrier density is in good agreement with self-consistent Poisson-Schrödinger calculations. However, a significant increase in the effective mass of 2DEG electrons at low... (More)

We report on the free charge carrier properties of a two-dimensional electron gas (2DEG) in an AlN/AlxGa1-xN high electron mobility transistor structure with a high aluminum content (x = 0.78). The 2DEG sheet density N s = (7.3 ± 0.7) × 10 12 cm-2, sheet mobility μ s = (270 ± 40) cm2/(Vs), sheet resistance R s = (3200 ± 500) ω / □, and effective mass m eff = (0.63 ± 0.04) m 0 at low temperatures (T = 5 K) are determined by terahertz (THz) optical Hall effect measurements. The experimental 2DEG mobility in the channel is found within the expected range, and the sheet carrier density is in good agreement with self-consistent Poisson-Schrödinger calculations. However, a significant increase in the effective mass of 2DEG electrons at low temperatures is found in comparison with the respective value in bulk Al0.78Ga22N (m eff = 0.334 m 0). Possible mechanisms for the enhanced 2DEG effective mass parameter are discussed and quantified using self-consistent Poisson-Schrödinger calculations.

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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Applied Physics Letters
volume
120
issue
25
article number
253102
publisher
American Institute of Physics (AIP)
external identifiers
  • scopus:85133206366
ISSN
0003-6951
DOI
10.1063/5.0087033
language
English
LU publication?
yes
id
89b88ab7-a8ae-4356-933c-6358d5a2cb4c
date added to LUP
2022-09-29 15:08:00
date last changed
2023-11-21 11:52:00
@article{89b88ab7-a8ae-4356-933c-6358d5a2cb4c,
  abstract     = {{<p>We report on the free charge carrier properties of a two-dimensional electron gas (2DEG) in an AlN/AlxGa1-xN high electron mobility transistor structure with a high aluminum content (x = 0.78). The 2DEG sheet density N s = (7.3 ± 0.7) × 10 12 cm-2, sheet mobility μ s = (270 ± 40) cm2/(Vs), sheet resistance R s = (3200 ± 500) ω / □, and effective mass m eff = (0.63 ± 0.04) m 0 at low temperatures (T = 5 K) are determined by terahertz (THz) optical Hall effect measurements. The experimental 2DEG mobility in the channel is found within the expected range, and the sheet carrier density is in good agreement with self-consistent Poisson-Schrödinger calculations. However, a significant increase in the effective mass of 2DEG electrons at low temperatures is found in comparison with the respective value in bulk Al0.78Ga22N (m eff = 0.334 m 0). Possible mechanisms for the enhanced 2DEG effective mass parameter are discussed and quantified using self-consistent Poisson-Schrödinger calculations. </p>}},
  author       = {{Kühne, Philipp and Armakavicius, Nerijus and Papamichail, Alexis and Tran, Dat Q. and Stanishev, Vallery and Schubert, Mathias and Paskov, Plamen P. and Darakchieva, Vanya}},
  issn         = {{0003-6951}},
  language     = {{eng}},
  month        = {{06}},
  number       = {{25}},
  publisher    = {{American Institute of Physics (AIP)}},
  series       = {{Applied Physics Letters}},
  title        = {{Enhancement of 2DEG effective mass in AlN/Al<sub>0.78</sub>Ga<sub>0.22</sub>N high electron mobility transistor structure determined by THz optical Hall effect}},
  url          = {{http://dx.doi.org/10.1063/5.0087033}},
  doi          = {{10.1063/5.0087033}},
  volume       = {{120}},
  year         = {{2022}},
}