Faculté des sciences

III-Nitride Nanostructures for Infrared Optoelectronics

Monroy, Eva ; Guillot, Fabien ; Leconte, Sylvain ; Bellet-Amalric, Edith ; Nevou, Laurent ; Doyennette, Laeticia ; Tchernycheva, Maria ; Julien, François H. ; Baumann, Esther ; Giorgetta, Fabrizio R. ; Hofstetter, Daniel ; Dang, Le Si

In: Acta Physica Polonica A (Proceedings of the XXXV International School of Semiconducting Compounds), 2006, vol. 110, no. 3, p. 295-301

Thanks to their large conduction band offset (~1.8 eV for the GaN/AlN system) and subpicosecond intersubband scattering rates, III-nitride heterostructures in the form of quantum wells or quantum dots are excellent candidates for high-speed unipolar devices operating at optical-fiber telecommunication wavelengths, and relying on the quantum confinement of electrons. In this work, we present the... Plus

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    Summary
    Thanks to their large conduction band offset (~1.8 eV for the GaN/AlN system) and subpicosecond intersubband scattering rates, III-nitride heterostructures in the form of quantum wells or quantum dots are excellent candidates for high-speed unipolar devices operating at optical-fiber telecommunication wavelengths, and relying on the quantum confinement of electrons. In this work, we present the plasma-assisted molecular-beam epitaxial growth of quantum well infrared photodetector structures. The growth of Si-doped GaN/AlN multiple quantum well structures is optimized by controlling substrate temperature, metal excess and growth interruptions. Structural characterization confirms a reduction of the interface roughness to the monolayer scale. P-polarized intersubband absorption peaks covering the 1.33-1.91 μm wavelength range are measured on samples with quantum well thickness varying from 1 to 2.5 nm. Complete intersubband photodetectors have been grown on conductive AlGaN claddings, the Al mole fraction of the cladding matching the average Al content of the active region. Photovoltage measurements reveal a narrow (~90 meV) detection peak at 1.39 μm at room temperature.