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Title: GaN/AlN Quantum Wells and Quantum Dots for Unipolar Devices at Telecommunication Wavelengths

Abstract

We report on the latest achievements in terms of growth and optical investigation of ultrathin GaN/AlN isolated and coupled quantum wells grown by plasma-assisted molecular-beam epitaxy. We also present the observation of intraband absorption in self-organized GaN quantum dots and on the application to infrared photodetection at telecommunication wavelengths.

Authors:
; ; ; ; ;  [1]; ; ;  [2]; ;  [3]
  1. Institut d'Electronique Fondamentale, Universite Paris Sud, UMR 8622 CNRS, 91405 Orsay (France)
  2. Equipe mixte CEACNRS-UJF, DRFMC/SP2M/PSC, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble (France)
  3. Departement of Electrical Engineering, Technion-Israel Institute of Technology, Haifa 3200 (Israel)
Publication Date:
OSTI Identifier:
21055058
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 893; Journal Issue: 1; Conference: ICPS 2006: 28. international conference on the physics of semiconductors, Vienna (Austria), 24-28 Jul 2006; Other Information: DOI: 10.1063/1.2729997; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION; ALUMINIUM NITRIDES; DATA TRANSMISSION; DEPOSITION; GALLIUM NITRIDES; MOLECULAR BEAM EPITAXY; PHOTODETECTORS; PLASMA; QUANTUM DOTS; QUANTUM WELLS; SEMICONDUCTOR MATERIALS; WAVELENGTHS

Citation Formats

Julien, Francois H., Tchernycheva, Maria, Doyennette, Laetitia, Nevou, Laurent, Lupu, Anatole, Warde, Elias, Guillot, Fabien, Monroy, Eva, Bellet-Amalric, Edith, Vardi, Alon, and Bahir, Gad. GaN/AlN Quantum Wells and Quantum Dots for Unipolar Devices at Telecommunication Wavelengths. United States: N. p., 2007. Web. doi:10.1063/1.2729997.
Julien, Francois H., Tchernycheva, Maria, Doyennette, Laetitia, Nevou, Laurent, Lupu, Anatole, Warde, Elias, Guillot, Fabien, Monroy, Eva, Bellet-Amalric, Edith, Vardi, Alon, & Bahir, Gad. GaN/AlN Quantum Wells and Quantum Dots for Unipolar Devices at Telecommunication Wavelengths. United States. doi:10.1063/1.2729997.
Julien, Francois H., Tchernycheva, Maria, Doyennette, Laetitia, Nevou, Laurent, Lupu, Anatole, Warde, Elias, Guillot, Fabien, Monroy, Eva, Bellet-Amalric, Edith, Vardi, Alon, and Bahir, Gad. Tue . "GaN/AlN Quantum Wells and Quantum Dots for Unipolar Devices at Telecommunication Wavelengths". United States. doi:10.1063/1.2729997.
@article{osti_21055058,
title = {GaN/AlN Quantum Wells and Quantum Dots for Unipolar Devices at Telecommunication Wavelengths},
author = {Julien, Francois H. and Tchernycheva, Maria and Doyennette, Laetitia and Nevou, Laurent and Lupu, Anatole and Warde, Elias and Guillot, Fabien and Monroy, Eva and Bellet-Amalric, Edith and Vardi, Alon and Bahir, Gad},
abstractNote = {We report on the latest achievements in terms of growth and optical investigation of ultrathin GaN/AlN isolated and coupled quantum wells grown by plasma-assisted molecular-beam epitaxy. We also present the observation of intraband absorption in self-organized GaN quantum dots and on the application to infrared photodetection at telecommunication wavelengths.},
doi = {10.1063/1.2729997},
journal = {AIP Conference Proceedings},
number = 1,
volume = 893,
place = {United States},
year = {Tue Apr 10 00:00:00 EDT 2007},
month = {Tue Apr 10 00:00:00 EDT 2007}
}
  • This work shows that the combination of ultrathin highly strained GaN quantum wells embedded in an AlN matrix, with controlled isotopic concentrations of Nitrogen enables a dual marker method for Raman spectroscopy. By combining these techniques, we demonstrate the effectiveness in studying strain in the vertical direction. This technique will enable the precise probing of properties of buried active layers in heterostructures, and can be extended in the future to vertical devices such as those used for optical emitters and for power electronics.
  • We demonstrate the formation of InAs quantum dots (QDs) on InAlAs/InP(111)A by means of droplet epitaxy. The C{sub 3v} symmetry of the (111)A substrate enabled us to realize highly symmetric QDs that are free from lateral elongations. The QDs exhibit a disk-like truncated shape with an atomically flat top surface. Photoluminescence signals show broad-band spectra at telecommunication wavelengths of 1.3 and 1.5 μm. Strong luminescence signals are retained up to room temperature. Thus, our QDs are potentially useful for realizing an entangled photon-pair source that is compatible with current telecommunication fiber networks.
  • Double heterostructures of strained GaN quantum wells (QWs) sandwiched between relaxed AlN layers provide a platform to investigate the quantum-confined electronic and optical properties of the wells. The growth of AlN/GaN/AlN heterostructures with varying GaN quantum well thicknesses on AlN by plasma molecular beam epitaxy (MBE) is reported. Photoluminescence spectra provide the optical signature of the thin GaN QWs. Reciprocal space mapping in X-ray diffraction shows that a GaN layer as thick as ∼28 nm is compressively strained to the AlN layer underneath. The density of the polarization-induced two-dimensional electron gas (2DEG) in the undoped heterostructures increases with the GaNmore » QW thickness, reaching ∼2.5 × 10{sup 13}/cm{sup 2}. This provides a way to tune the 2DEG channel density without changing the thickness of the top barrier layer. Electron mobilities less than ∼400 cm{sup 2}/Vs are observed, leaving ample room for improvement. Nevertheless, owing to the high 2DEG density, strained GaN QW field-effect transistors with MBE regrown ohmic contacts exhibit an on-current density ∼1.4 A/mm, a transconductance ∼280 mS/mm, and a cut off frequency f{sub T}∼104 GHz for a 100-nm-gate-length device. These observations indicate high potential for high-speed radio frequency and high voltage applications that stand to benefit from the extreme-bandgap and high thermal conductivity of AlN.« less
  • We study the nucleation of GaN islands grown by plasma-assisted molecular-beam epitaxy on AlN in a Stranski-Krastanov mode. In particular, we assess the variation of their height and density as a function of GaN coverage. We show that the GaN growth passes four stages: initially, the growth is layer-by-layer; subsequently, bidimensional precursor islands form, which transform into genuine three-dimensional islands. During the latter stage, the height and the density of the islands increase with GaN coverage until the density saturates. During further GaN growth, the density remains constant and a bimodal height distribution appears. The variation of island height andmore » density as a function of substrate temperature is discussed in the framework of an equilibrium model for Stranski-Krastanov growth [R. E. Rudd et al., Phys. Rev. Lett. 90, 146101 (2003)].« less
  • The investigation of small-size embedded nanostructures, by a combination of complementary anomalous diffraction techniques, is reported. GaN quantum dots (QD's), grown by molecular beam epitaxy in a modified Stranski-Krastanow mode, are studied in terms of strain and local environment, as a function of the AlN cap layer thickness, by means of grazing-incidence anomalous diffraction. That is, the x-ray photon energy is tuned across the Ga absorption K edge which makes diffraction chemically selective. Measurement of hkl scans, close to the AlN (3030) Bragg reflection, at several energies across the Ga K edge, allows the extraction of the Ga partial structuremore » factor, from which the in-plane strain of GaN QD's is deduced. From the fixed-Q energy-dependent diffracted intensity spectra, measured for diffraction-selected isostrain regions corresponding to the average in-plane strain state of the QD's, quantitative information regarding the composition and out-of-plane strain has been obtained. We recover the in-plane and out-of-plane strains in the dots. The comparison to the biaxial elastic strain in a pseudomorphic layer indicates a tendency to an overstrained regime.« less