Open AccessCathodoluminescence, High‐Resolution X‐Ray Diffraction and Transmission‐Electron‐Microscopy Investigations of Cubic AlGaN/GaN Quantum Wells
Author(s) -
As D.J.,
Köhler U.,
Potthast S.,
Khartchenko A.,
Lischka K.,
Potin V.,
Gerthsen D.
Publication year - 2002
Publication title -
physica status solidi (c)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 46
eISSN - 1610-1642
pISSN - 1610-1634
DOI - 10.1002/pssc.200390036
Subject(s) - cathodoluminescence , transmission electron microscopy , materials science , molecular beam epitaxy , quantum well , superlattice , diffraction , dislocation , electron diffraction , high resolution transmission electron microscopy , coalescence (physics) , crystallography , optoelectronics , epitaxy , optics , luminescence , chemistry , nanotechnology , physics , laser , layer (electronics) , astrobiology , composite material
The structural and optical properties of cubic Al 0.25 Ga 0.75 N/GaN multi quantum well structures grown on GaAs (001) substrates by radio‐frequency plasma‐assisted molecular beam epitaxy (MBE) are reported. Transmission electron microscopy (TEM), high resolution X‐ray diffraction (HRXRD), and cathodoluminescence (CL) measurements are used to characterize the cubic Al 0.25 Ga 0.75 N/GaN quantum wells. The interfaces between the quantum‐well and barrier layers are well resolved, abrupt and the entire structure shows an excellent periodicity. Due to the high dislocation density of about 10 10 cm –2 a severe broadening of the XRD‐reflection is observed and superlattice satellite peaks are only weakly indicated. Further, a wavy structure is seen in TEM at the coalescence of submicron‐size grains. Nevertheless, CL at room temperature shows a strong emission of quantized states at 3.352 eV.