DX centers in AlAs and GaAs-AlAs selectively doped superlattices

Effects of D-Doping on Characteristics of AlAs/GaAs Barriers Grown by Mba at 400 ??C

Effects of d-doping on barriers effective heights and series resistance of highly doped n-type GaAs/AIAs/GaAs/AlAs/GaAs heterostructures, grown by molecular beam epitaxy (MBE) at 400?°C, have been studied. As it was expected, inclusion of an n+ d-doped layer at each hetero-interface has reduced the barriers heights and series resistance of the structure significantly, while p+ d-doped layers ha...

Layer ordering and faulting in (GaAs)n/(AlAs)n ultrashort-period superlattices.

We report studies of (GaAs)(n)/(AlAs)(n) ultrashort-period superlattices using synchrotron x-ray scattering. In particular, we demonstrate that interfaces of these superlattices contain features on two different length scales: namely, random atomic mixture and ordered mesoscopic domains. Both features are asymmetric on the two interfaces (AlAs-on-GaAs and GaAs-on-AlAs) for n>2. Periodic composi...

Influence of various growth parameters on the interface abruptness of AlAs/GaAs short period superlattices

Cross-sectional scanning tunneling microscopy has been used to investigate the effects of several key growth parameters on the resulting interfacial quality of AlAs/GaAs short period superlattices. For growth on top of AlGaAs layers, only superlattices grown with periodicity no smaller than 4 unit cells of GaAs and 2 unit cells of AlAs and grown with a minimum of 30 s of growth interrupt time a...

Strong heavy-to-light hole intersubband absorption in the valence band of carbon-doped GaAs/AlAs superlattices

Localization and band-gap pinning in semiconductor superlattices with layer-thickness fluctuations

We consider (AlAs)n/(GaAs)n superlattices with random thickness fluctuations ∆n around the nominal period n. Using three-dimensional pseudopotential plane-wave band theory, we show that (i) any amount ∆n/n of thickness fluctuations leads to band-edge wavefunction localization, (ii) for small ∆n/n the SL band gap is pinned at the gap level produced by a single layer with “wrong” thickness n+∆n, ...