Strained semiconductor nanostructures

We apply strained layer heteroepitaxial growth to create two- and three-dimensional quantum dot (QD) crystals, SiGe heterostructures with unique optical and electronic properties as well as radial superlattices and accurately positioned semiconductor nanopipelines. The high degree of structural perfection of the QD crystals allows us to observe novel phenomena such as lateral strain field interferences. SiGe based heterostructures and interband tunnelling diodes, grown at extremely low temperatures (≈300°C), emit at wavelengths beyond 2 µm and experience peak-to-valley current ratios larger than 7:1. Furthermore, we roll up strained semiconductor bilayers and show that the walls of these structures consist of novel radial superlattices. Individual rolled-up nanotubes are filled up with red dye fluid.