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The authors propose and demonstrate an alternative memory concept in which a storage island is connected to a nanowire containing a stack of nine InAs quantum dots, each separated by thin InP tunnel barriers. Transport through the quantum dot structure is suppressed for a particular biasing window due to misalignment of the energy levels. This leads to hysteresis in the charging/discharging of the storage island. The memory operates for temperatures up to around 150K and has write times down to at least 15ns. A comparison is made to a nanowire memory based on a single, thick InP barrier.

Raman scattering by local vibrational modes has been used to study the incorporation of Si in single δ‐doped GaAs layers. Placing the doping spike at different depths underneath the surface, a depth profile of the dopant concentration incorporated on lattice sites has been obtained. For samples grown by molecular beam epitaxy under conditions which are known to lead to a significant broadening of the doping spike, the applied Raman technique reveals the incorporation of Si on Ga sites with a broadening of the Si distribution in excess of 20 nm.

Photoluminescence and photoluminescence excitation measurements at temperatures ranging from 4 to 300 K were performed on 9.2‐nm GaSb quantum wells confined by AlSb‐GaSb short‐period superlattices. In the temperature range 4–200 K the photoluminescence from the high‐quality molecular beam epitaxially grown samples is dominated by free‐exciton emission. This assignment is confirmed by photoluminescence excitation spectroscopy which reveals an energy separation of 11.5 meV between n=1 heavy‐hole and n=1 light‐hole free excitons for the 9.2‐nm wells. At low temperatures the photoluminescence line is shifted by only 7.5 meV to low energy from the heavy‐hole excitonic peak observed in the excitation spectrum. This small value of the Stokes shift indicates the absence of impurity‐related trapping of excitons.