TY  - JOUR
A1  - Pietsch, Ullrich
A1  - Grenzer, Jörg
A1  - Grigorian, Souren A.
A1  - Weyers, Markus
A1  - Zeimer, Ute
A1  - Feranchuk, S.
A1  - Fricke, J.
A1  - Kissel, H.
A1  - Knauer, A.
A1  - Tränkle, G.
T1  - Nanoengineering of lateral strain-modulation in quantum well heterostructures
N2  - We have developed a method to design a lateral band-gap modulation in a quantum well heterostructure. The lateral strain variation is induced by patterning of a stressor layer grown on top of a single quantum well which itself is not patterned. The three-dimensional (3D) strain distribution within the lateral nanostructure is calculated using linear elasticity theory applying a finite element technique. Based on the deformation potential approach the calculated strain distribution is translated into a local variation of the band-gap energy. Using a given vertical layer structure we are able to optimize the geometrical parameters to provide a nanostructure with maximum lateral band-gap variation. Experimentally such a structure was realized by etching a surface grating into a tensile-strained InGaP stressor layer grown on top of a compressively strained InGaAs-single quantum well. The achieved 3D strain distribution and the induced band-gap variation are successfully probed by x-ray grazing incidence diffraction and low-temperature photoluminescence measurements, respectively
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Talalaev, V
A1  - Tomm, JW
A1  - Elsaesser, T
A1  - Zeimer, Ute
A1  - Fricke, J
A1  - Knauer, A
A1  - Kissel, H
A1  - Weyers, Markus
A1  - Tarasov, GG
A1  - Grenzer, Jörg
A1  - Pietsch, Ullrich
T1  - Carrier dynamics in laterally strain-modulated InGaAs quantum wells
N2  - We investigate the transient recombination and transfer properties of nonequilibrium carriers in an In0.16Ga0.84As/GaAs quantum well (QW) with an additional lateral confinement implemented by a patterned stressor layer. The structure thus contains QW- and quantum-wire-like areas. At low excitation densities, photoluminescence (PL) transients from both areas are well described by a rate equation model for a three-level system with a saturable interlevel carrier transfer representing the lateral drift of carriers from the QW regions into the wires. Small-signal carrier lifetimes for QW, wires, and transfer time from QW to wire are 180, 190, and 28 ps, respectively. For high excitation densities the time constants of the observed transients increase, in agreement with the model. In addition, QW and wire PL lines merge indicating a smoothening of the potential difference, i.e., the effective carrier confinement caused by the stressor structure becomes weaker with increasing excitation. (c) 2005 American Institute of Physics
Y1  - 2005
ER  -