Self-organized InGaAs quantum dots for advanced applications in optoelectronics

Abstract
We report on fabrication of quantum dot (QDs) heterostructures for applications in optoelectronics. Different kinds of QDs are used: (i) three-dimensional quantum dots obtained by Stranski-Krastanow or Volmer-Weber growth of three-dimensional QDs in the InAs-GaAs material system, (ii) two-dimensionally-shaped QDs formed by submonolayer insertions in the InAs-GaAs and similar systems, (iii) GaAs clusters formed on corrugated (311)A AlAs surfaces, (iv) and quantum dots obtained by spinodal decomposition and activated spinodal decomposition in InGaAs-GaAs and InGaAsN-GaAs materials system. Formation of QDs uniform in size and shape is possible in all approaches and is governed, mostly, by thermodynamics. Ultrahigh modal gain can be achieved in ultradense arrays of very small quantum dots in wide gap matrices. 1.3-1.7 /spl mu/m emission can be achieved using InAs-GaAs QDs. Recent advances in growth make it possible to realize GaAs 1.3 /spl mu/m CW VCSEL with /spl sim/0.7 mW output power and long operation lifetime.