Behn, U, Misra, P, Grahn, H T, Imer, B, Nakamura, S, DenBaars, S P, ...
We have used polarized photoreflectance spectroscopy to study the electronic-band-structure modification of GaN films grown along different nonpolar orientations due to biaxial, anisotropic in-plane...
Optical polarization anisotropy in strained A-plane GaN films on R-plane sapphire (2006)
Ghosh, S, Misra, P, Grahn, H T, Imer, B, Nakamura, S, DenBaars, S P, ...
We have used polarized photoreflectance (PR) spectroscopy to study [1120]-oriented A-plane GaN films on R-plane sapphire substrates. For this type of films, the c-axis of GaN lies in the film plane....
Misra, P, Behn, U, Brandt, O, Grahn, H T, Imer, B, Nakamura, S, ...
We use photoreflectance (PR) spectroscopy to study the electronic band structure modification of GaN films grown along different nonpolar orientations due to biaxial, anisotropic in-plane strain. The...
Intraband coherence of bloch oscillations after momentum scattering (2004)
Nüsse, S., Wolter, F., Haring Bolivar, P., Köhler, K., Hey, R., Grahn, H.T., ...
Resonantly excited secondary emission of light (RSE) in GaAs/AlGaAs superlattices gives a direct proof for the stability of coherent Bloch dynamics beyond the optical coherent regime. The...
Watson, I.M.*, Jahn, U., Dahr, S., Brandt, O., Grahn, H.T., Ploog, K.H.
We study the quantum efficiency () and transition energy (Et) as a function of excitation density and temperature in (In,Ga)N/GaN multiple quantum wells (MQWs) fabricated by molecular-beam epitaxy...
Watson, I.M., Jahn, U., Dahr, S., Brandt, O., Grahn, H.T., Ploog, K.H.
We study the quantum efficiency () and transition energy (Et) as a function of excitation density and temperature in (In,Ga)N/GaN multiple quantum wells (MQWs) fabricated by molecular-beam epitaxy...
Watson, I.M., Jahn, U., Dahr, S., Brandt, O., Grahn, H.T., Ploog, K.H.
We study the quantum efficiency () and transition energy (Et) as a function of excitation density and temperature in (In,Ga)N/GaN multiple quantum wells (MQWs) fabricated by molecular-beam epitaxy...
Sun, Y J, Brandt, O, Cronenberg, S, Dhar, S, Grahn, H T, Ploog, K H, ...
M-plane In0.1Ga0.9N(1 (1) over bar 00) multiple quantum wells were grown on gamma-LiAlO2(100) by plasma-assisted molecular-beam epitaxy. The high brightness of the photoluminescence of these multiple...
Time-Resolved Studies of Exciton Recombination in Direct-Gap GaAs/AlAs Superlattices (2002)
Litovchenko, V. G., Korbutyak, D. V., Krylyuk, S. G., Grahn, H. T., Ploog, K.
The temperature dependence of the recombination dynamics of excitons was investigated by time-resolved photoluminescence spectroscopy in direct-gap GaAs/AlAs superlattices. Peculiarities of excitonic...
Time-resolved photoluminescence study of excitons in hexagonal GaN layers grown on sapphire. (1998)
Pau, S., Liu, Z., Kuhl, J., Ringling, J., Grahn, H. T., Khan, M. A., ...
Electrically tunable GHz oscillations in doped GaAs-AlAs superlattices (1997)
Kastrup, J., Hey, R., Ploog, K. H., Grahn, H. T., Bonilla, L. L., Kindelan, M., ...
Tunable oscillatory modes of electric-field domains in doped semiconductor superlattices are reported. The experimental investigations demonstrate the realization of tunable, GHz frequencies in...
Influence of LO-phonon emission on bloch oscillations in semiconductor superlattices (1997)
Wolter, F., Roskos, H.G., Haring Bolivar, P., Bartels, G., Kurz, H., Köhler, K., ...
The intraband phase coherence of electronic Bloch wavepackets in semiconductor superlattices is partially conserved when electrons undergo energy relaxation by LO-phonon emission. The decay time of...
Excitonic effects in miniband and Wannier-Stark absorption spectra (1995)
Linder, N., Schmidt, K.H., Geisselbrecht, W., Döhler, G.H., Grahn, H.T., Ploog, K., ...
We compare experimental and theoretical electroabsorption spectra of strongly coupled GaAs/AlAs superlattices for the full field range from the Franz-Keldysh (low field) to the Wannier-Stark (high...
Coexistence of the Franz-Keldysh and Wannier-Stark effect in semiconductor superlattices (1995)
Linder, N., Schmidt, K.H., Geisselbrecht, W., Döhler, G.H., Grahn, H.T., Ploog, K., ...
The optical absorption of short-period semiconductor superlattices with an electric field perpendicular to the layer plane is studied. The applied fields cover the range from the "miniband regime"...
Schmidt, K.H., Linder, N., Döhler, G.H., Grahn, H.T., Ploog, K., Schneider, H.
Using differential photocurrent spectroscopy we have studied the field dependent absorption in a GaAs/AlAs superlattices, which have only one monolayer AlAs barriers, with unpreceded dynamical...
Line shape of electroreflectance spectra in semiconductor superlattices (1993)
Behn, U., Grahn, H.T., Ploog, K., Schneider, H.
Electroreflectance (ER) spectra of GaAs-AlAs superlattices in a perpendicular electric field exhibit complicated line shapes that cannot be explained by the presence of heavy-hole and light-hole...
Behn, U., Grahn, H.T., Schneider, H., Ploog, K.
Electroreflectance (ER) spectroscopy has been used to study the influence of an electric field on the optical properties of a strongly coupled GaAs-AlAs superlattice. At certain electric field...
Resonance-induced delocalization of electrons in GaAs-AlAs supperlattices (1990)
Grahn, H.T., Klitzing, K. Von, Ploog, K., Schneider, H.
We report on novel interaction phenomena between different Stark ladders in a strongly coupled GaAs-AlAs superlattice. We observe an anticrossing behaviour between certain exciton states if the...
Optical detection of resonant tunneling in GaAs/AlAs superlattices. (1990)
Grahn, H.T., Klitzing, K. Von, Ploog, K., Schneider, H.
We report on the investigation of the miniband transport regime in GaAs-AlAs superlattices by electrical time-of-flight experiments. The temperature dependence of the low-field drift mobility is used...
Grahn, H.T., Rühle, W.W., Klitzing, K. Von, Ploog, K., Schneider, H.
We report on the observation of photoluminescence from the second and third electronic subbands in undoped GaAs-AlAs superlattices under application of an electric field perpendicular to the layers....
Miniband transport in GaAs-AlAs superlattices. (1990)
Grahn, H.T., Klitzing, K. Von, Ploog, K., Schneider, H.
We report on the investigation of the miniband transport regime in GaAs-AlAs superlattices by electrical time-of-flight experiments. The temperature dependence of the low-field drift mobility is used...
Electro-optical multistability in GaAs/AlAs superlattices at room temperature. (1990)
Grahn, H.T., Klitzing, K. Von, Fujiwara, K., Ploog, K., Schneider, H.
We have studied the optical absorption properties of a GaAs/AlAs short-period superlattice at room temperature in an electric field perpendicular to the layers. Several pronounced optical transitions...