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Semiconductor heterostructures

QD Struktur

Semiconductor quantum-well and quantum-dot structures are important base materials for numerous optoelectronic devices in communication technology (light-emitting diodes - LEDs -, laser diodes and photodetectors). Future spintronic devices and devices for quantum information processing are also potential devices based on semiconductor heterostructures. The wavelength of LEDs and semiconductor lasers is determined by the band gap energy of the used material system, i.e. the chemical composition, and the sizes of quantum wells and quantum dots. Particularly interesting for light-emitting devices are wavelengths of 1.3 µm and 1.55 µm where optical fibers have absorption minima. 

We study the structural properties and chemical composition of different semiconductor heterostructures on the nanoscale to correlate the structural and chemical properties with electronic and optical characteristics.


InAs/GaAs quantum dot structures

CdSe/ZnSe quantum dot structures

"Spin-aligning" ZnMnSe layers and MnSe/ZnSe hetero structures

Spin LEDs

Gruppe-III-Nitrid hetero structures

 

 

Selected publications:

[1] I.P. Soshnikov, N.N. ldentsov, A.F. Tsatsul´nikov, A.V. Sakharov, W.V. Lundin, E.A. Zavarin, A.V. Fomin, D. Litvinov, E. Hahn, D. Gerthsen, Special features of structural interaction in (AlGaIn)N/GaN heterostructures used as dislocation filters,
Semiconductors 39, 100 (2005)

[2] W. Löffler, D. Tröndle, J. Fallert, H. Kalt, D. Litvinov, D. Gerthsen, J. Lupaca-Schomber, T. Passow,
B. Daniel, J. Kvietkova, M. Grün, C. Klingshirn, M. Hetterich,
Electrical spin injection from ZnMnSe into InGaAs quantum wells and quantum dots,
Appl. Phys. Lett. 88, 062105 (2006)

[3] D. Litvinov, D. Gerthsen, A. Rosenauer, M. Schowalter, T. Passow, M. Hetterich,
Transmission electron microscopy investigation of segregation and critical floating-layer
content of indium for island formation in InGaAs,
Phys. Rev. B 74, 165306 (2006)

[4] W. Löffler, D. Tröndle, J. Fallert, E. Tsitsishvili, H. Kalt, D. Litvinov, D. Gerthsen, J. Lupaca-Schomber,
T. Passow, B. Daniel, J. Kvietkova, M. Hetterich,
Electrical spin injection into InGaAs quantum dots,
Phys. Stat. Sol. C, 3, 2406 (2006)

[5] D. Litvinov, D. Gerthsen, A. Rosenauer, M. Schowalter, T. Passow, M. Hetterich,
The role of segregation in InGaAs heteroepitaxy,
Mat. Sci. For. 239-543, 3540 (2007)

[6] T. Passow, S. Li, P. Feinäugle, Th. Vallaitis, J. Leuthold, D. Litvinov, D. Gerthsen, M. Hetterich,
Systematic investigation of the influence of growth conditions on InAs/GaAs quantum dot properties,
J. Appl. Phys. 102, 073511 (2007)

[7] D. Litvinov, H. Blank, R. Schneider, D. Gerthsen, T. Vallaitis, J. Leuthold, T. Passow, A. Grau, H. Kalt, C. Klingshirn, M. Hetterich, Influence of InGaAs cap layers with different In concentration on the properties of InGaAs quantum dots,
J. Appl. Phys. 103, 083532-1-8 (2008)

[8] D. Litvinov, M. Schowalter, A. Rosenauer, B. Daniel, J. Fallert, W. Löffler, H. Kalt, M. Hetterich,
Determination of critical thickness for defect formation of CdSe/ZnSe heterostructures by transmission electron microscopy
and photoluminescence spectroscopy,
Phys. Stat. Sol. A, 205, 2892 (2008)

[9] B.C. Richards, J. Hendrickson, J. Sweet, G. Khitrova, D. Litvinov, D. Gerthsen, B. Myer, S. Pau,
D. Sarid, M. Wegener, E. L. Ivchenko, A. N. Poddubny, and H. M. Gibbs
Attempts to grow optically coupled Fibonacci-spaced InGaAs/GaAs quantum wells always result in surface gratings
Opt. Express 16, 21512 (2008)

[10] A. Chernikov, S. Horst, S.W. Koch, S. Chatterjee, W.W. Rühle, J. Sweet, B. Richards, J. Hendrickson,
G. Khitrova, H.M. Gibbs, D. Litvinov, D. Gerthsen, M. Wegener
Intra-dot relaxation and dephasing rates from time-resolved photoluminescence from InAs quantum dot ensembles
Solid State Comm. 149, 1486 (2009)

[11] J. Sweet, B.C. Richards, J. D. Olitzky, J. Hendrickson, G. Khitrova, H.M. Gibbs, D. Litvinov, D. Gerthsen,
D.Z. Hu, D. M. Schaadt, M. Wegener, U. Khankhoje and A. Scherer
GaAs photonic crystal slab nanocavities: Relating observed surface roughness and Q
Photonics and Nanostructures 8, 1 (2010)

[12] I. Tischer, M. Feneberg, M. Schirra, H. Yacoub, R. Sauer, K. Thonke, T. Wunderer,
F. Scholz, L. Dieterle, E. Müller, D. Gerthsen
I2 basal plane stacking fault in GaN: Origin of the 3.32 eV luminescence band
Phys. Rev. B 83, 035314 (2011)

[13] I. Tischer, M. Feneberg, M. Schirra, H. Yacoub, R. Sauer, K. Thonke, T. Wunderer, F. Scholz, L. Dieterle, E. Müller, D. Gerthsen
Stacking fault-related luminescence features in semi-polar GaN I2 basal plane stacking fault in GaN:
origin of the 3.32 eV luminescence band Phys.
Status Solidi B 248, 611 (2011)

[14] M. Helfrich, R. Gröger, A. Förste, D. Litvinov, D. Gerthsen, T. Schimmel, D.M. Schaadt
Investigation of pre-structured GaAs surfaces for subsequent site-selective InAs quantum dot growth
Nanoscale Res. Lett. 6, 211 (2011)

[15] A.F. Tsatsulnikov, W.V. Lundin, E.E. Zavarin, A.E. Nikolaev, A.V. Sakharov, V.S. Sizov, S.O. Usov, Yu. G. Musikhin, D. Gerthsen,
Influence of hydrogen on local phase separation in InGaN thin layers and properties of light-emitting structures based on TEM
Semiconductors 45, 271 (2011)

[16] P. Asshoff, G. Wüst, A. Merz, D. Litvinov, D. Gerthsen, H. Kalt, M. Hetterich,
Nuclear spin-polarization in single self-assembled InGaAs quantum dots by electrical spin-injection
Phys. Rev. B 84, 125302 (2011)

[17] M. Helfrich, D.Z. Hu, J. Hendrickson, M. Gehl, D. Rülke, R. Gröger, D. Litvinov, S. Linden, M. Wegener,
D. Gerthsen,T. Schimmel, M. Hetterich, H. Kalt, G. Khitrova, H. Gibbs, D.M. Schaadt
Growth and annealing of InAs quantum dots on pre-structured GaAs substrates
J. Cryst. Growth 323, 187 (2011)

[18]D. Litvinov, D. Gerthsen, R. Vöhringer, D.Z. Hu, D.M. Schaadt
TEM investigation of AlN Growth on Si(111)
J. Cryst. Growth 338, 283 (2012)

[19] R. Walther, D. Litvinov, M. Fotouhi, R. Schneider, D. Gerthsen, R. Vöhringer, D.Z. Hu, D.M. Schaadt
Microstructure of PAMBE-grown InN layers on Si(111)
J. Cryst. Growth 340, 44 (2012)