Studies of GaInAs/InP quantum dots processed from aerosol deposited particles

We report a fabrication technology for the production of large quantities of GaInAs/InP quantum dot structures with typical lateral sizes in the range of 20-30 nm. This technique includes the use of sintered aerosol Ag particles as an etching mask in a plasma etching process and epitaxial overgrowth. Transmission electron microscopy shows that the sintered silver particles are almost spherical and monocrystalline. The etching process results in free standing columns with densities around 10⁹ cm^-2. Scanning electron microscopy indicated a narrow deviation in width as well as in height of the columns. Scanning tunneling spectroscopy revealed both electron depletion and a slight widening of the band gap in InP columns. Both as etch and overgrown GaInAs/InP columns were characterized by low-temperature cathodoluminescence. The overgrown dots showed a significant improvement in quantum efficiency as compared to the as etched columns