Self-organized quantum dots and quantum dot lasers (invited)

The growth and characterization of two types of self-organized quantum dots, Stranski-Krastanow (S-K) mode grown quantum dots and atomic layer epitaxy (ALE) grown quantum dots, are described. In the S-K mode growth, molecular beam epitaxy has been used. Multilayer stacked structures have been fabricated. S-K mode grown quantum dots showed the ground state photoluminescence (PL) emission wavelength of 1.14 mu m and the full width at half maximum of the emission linewidth of 80 meV. ALE mode grown quantum dots are fabricated using metalorganic chemical vapor deposition. A smaller PL linewidth of 40 meV, indicating a higher uniformity in the size and composition of quantum dots, and a room temperature emission at 1.3 mu m were obtained. Continuous wave lasing at the ground state at room temperature was achieved with a S-K mode frown quantum dot laser owing to the high dot density enabled by the stacked dot layer structure. Because of the low density of dots, lasing was at 80 K at the higher order sublevel in ALE grown quantum dot lasers. Based on these experimental results, we discuss the key issues involved in these fabrication technologies and the carrier dynamics to achieve the ideal performance for quantum dot lasers. (C) 1998 American Vacuum Society. [S0734-2101(98)04902-1].