Carrier delocalization in InAs/InGaAlAs/InP quantum-dash-based tunnel injection system for 1.55 µm emission
W. Rudno-Rudziński,
M. Syperek,
J. Andrzejewski,
A. Maryński,
J. Misiewicz,
A. Somers,
S. Höfling,
J. P. Reithmaier,
G. Sęk
Affiliations
W. Rudno-Rudziński
Department of Experimental Physics, Faculty of Fundamental Problems of Technology, University of Science and Technology, St. Wyspiańskiego 27, 50-370 Wrocław, Poland
M. Syperek
Department of Experimental Physics, Faculty of Fundamental Problems of Technology, University of Science and Technology, St. Wyspiańskiego 27, 50-370 Wrocław, Poland
J. Andrzejewski
Department of Experimental Physics, Faculty of Fundamental Problems of Technology, University of Science and Technology, St. Wyspiańskiego 27, 50-370 Wrocław, Poland
A. Maryński
Department of Experimental Physics, Faculty of Fundamental Problems of Technology, University of Science and Technology, St. Wyspiańskiego 27, 50-370 Wrocław, Poland
J. Misiewicz
Department of Experimental Physics, Faculty of Fundamental Problems of Technology, University of Science and Technology, St. Wyspiańskiego 27, 50-370 Wrocław, Poland
A. Somers
Technische Physik, University of Würzburg and Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems, Am Hubland, D 97074 Würzburg, Germany
S. Höfling
Technische Physik, University of Würzburg and Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems, Am Hubland, D 97074 Würzburg, Germany
J. P. Reithmaier
Institute of Nanostructure Technologies and Analytics, Technische Physik, Universitaet Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
G. Sęk
Department of Experimental Physics, Faculty of Fundamental Problems of Technology, University of Science and Technology, St. Wyspiańskiego 27, 50-370 Wrocław, Poland
We have investigated optical properties of hybrid two-dimensional-zero-dimensional (2D-0D) tunnel structures containing strongly elongated InAs/InP(001) quantum dots (called quantum dashes), emitting at 1.55 μm. These quantum dashes (QDashes) are separated by a 2.3 nm-width barrier from an InGaAs quantum well (QW), lattice matched to InP. We have tailored quantum-mechanical coupling between the states confined in QDashes and a QW by changing the QW thickness. By combining modulation spectroscopy and photoluminescence excitation, we have determined the energies of all relevant optical transitions in the system and proven the carrier transfer from the QW to the QDashes, which is the fundamental requirement for the tunnel injection scheme. A transformation between 0D and mixed-type 2D-0D character of an electron and a hole confinement in the ground state of the hybrid system have been probed by time-resolved photoluminescence that revealed considerable changes in PL decay time with the QW width changes. The experimental discoveries have been explained by band structure calculations in the framework of the eight-band k⋅p model showing that they are driven by delocalization of the lowest energy hole state. The hole delocalization process from the 0D QDash confinement is unfavorable for optical devices based on such tunnel injection structures.