Characterisation and optimisation of MBE grown arsenide/antimonide interfaces

We report on molecular beam epitaxial growth and structural characterisatio ns of unintentionally-doped InAs/AlSb strained multiple quantum wells grown on GaSb substrates. The crystalline quality and the interface roughness ob tained using different cell shutter sequences at the arsenide/antimonide in terfaces are compared by high resolution X-ray diffraction and small angle X-ray reflectivity measurements. Optical characterisations by photo-induced absorption spectroscopy are then carried out. A strong e1 --> e2 p-polaris ed intersubband absorption is observed in the mid infrared with a narrow br oadening factor, revealing the good material quality of the sampler. (C) 20 01 Elsevier Science B.V. All rights reserved.