Effect of the wetting layer (WL) on the output power of a double tunneling-injection (DTI) quantum dot (QD) laser is studied. Such a laser was proposed earlier to suppress bipolar population and hence electron-hole recombination outside QDs. In the Stranski-Krastanow growth mode, QDs are formed on an initially grown WL. The WL is directly connected to QDs by the processes of carrier capture and thermal escape. These processes are described in terms of the temporal cross-sections of electron and hole capture from the WL into QDs. The electron and hole densities and parasitic electron-hole recombination current density in the WL, and the output power of the device are calculated as functions of the temporal cross-sections. These calculations provide the basis for optimization of a DTI QD laser with the WL aimed at maximizing the output power. The larger the temporal cross-section of electron capture into QDs, the more efficient is the electron capture from the WL into QDs, and hence the higher is the output power. The smaller the temporal crosssection of hole capture into QDs, the less intensive is the hole thermal escape from QDs into the WL, the less intensive is the recombination in the WL, and hence the higher is the output power.

Date Published: 24 February 2010
PDF: 12 pages
Proc. SPIE 7610, Quantum Dots and Nanostructures: Synthesis, Characterization, and Modeling VII, 76100T (24 February 2010);

Published in SPIE Proceedings Vol. 7610:
Quantum Dots and Nanostructures: Synthesis, Characterization, and Modeling VII
Kurt G. Eyink; Frank Szmulowicz; Diana L. Huffaker, Editor(s)