MBE Growth and Optical Properties of Novel Corrugated-Interface Quantum Wells

We have systematically studied MBE growth and properties of novel corrugated-interface quantum wells, where the GaAs well thickness is modulated with the average period of 32 Å–324 Å along the interface for possible formation of quantum wire states. The modulation is attempted by the alternate deposition of fractional monolayer of GaAs and AlAs on (001) flat and slightly misoriented substrates. Although the 2-dimensional nucleation is dominant in the growth of AlAs at a lower substrate temperature (T s<600°C) and prevents the formation of modulation, the growth mode on the most misoriented planes is transformed to step flow at a higher T s (≧640°C) under the appropriate growth rate and V/III flux ratio, leading to the formation of quasi-periodic GaAs/AlAs or Al xAGa1-xAAs/Al xBGa1-xBAs modulated structures. Measured photoluminescence energies are compared with the theory to demonstrate the composition modulation and the laterally confined quasi-one-dimensional electronic states along the interfaces and also to estimate the periodicity fluctuation and the compositional mixing in GaAs-AlAs modulated structures.