Beteiligte:
Gmachl, Claire;
Ng, Hock M.;
Cho, Alfred Y.
Erschienen:
AIP Publishing, 2001
Erschienen in:
Applied Physics Letters, 79 (2001) 11, Seite 1590-1592
Sprache:
Englisch
DOI:
10.1063/1.1403277
ISSN:
0003-6951;
1077-3118
Entstehung:
Anmerkungen:
Beschreibung:
Intersubband absorption in coupled GaN/AlGaN double quantum wells (DQWs) has been measured. The samples were grown by molecular-beam epitaxy on a sapphire substrate and with large (0.65 or 0.9) AlN-mole fraction in the barriers. Peak absorption wavelengths as short as 1.35 and 1.52 μm were measured for a symmetric DQW of 12 Å wide wells coupled by a 10 Å wide barrier, which also showed evidence of excited-state anticrossing. As expected, asymmetric DQWs displayed no such anticrossing, and the ground-state anticrossing energies were found to be much smaller, as a result of the comparatively large effective electron mass, than the energy broadening of individual transitions. Degenerate doping of the DQWs was used to establish a common reference energy at the Fermi level, which allows overcoming uncertainties related to intrinsic internal electric fields. The asymmetric DQWs displayed peak absorption wavelengths between 1.5 and 2.9 μm.