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  1. Article

    Open Access

    Fermi level and bands offsets determination in insulating (Ga,Mn)N/GaN structures

    The Fermi level position in (Ga,Mn)N has been determined from the period-analysis of GaN-related Franz-Keldysh oscillation obtained by contactless electroreflectance in a series of carefully prepared by molecu...

    L. Janicki, G. Kunert, M. Sawicki, E. Piskorska-Hommel, K. Gas… in Scientific Reports (2017)

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  2. No Access

    Article

    Optical polariton properties in ZnSe-based planar and pillar structured microcavities

    Strong coupling is demonstrated in monolithic ZnSe-based microcavities. Under nonresonant excitation the polariton dispersion has been investigated in dependence on the photon-exciton detuning for different e...

    K. Sebald, A. Trichet, M. Richard, L. S. Dang… in The European Physical Journal B (2011)

  3. No Access

    Article

    Studies on Carbon as Alternative P-Type Dopant for Gallium Nitride

    GaN layers were grown by molecular beam epitaxy and doped with carbon of nominal concentrations ranging from 1016 cm-1 to 10 20 cm-1. The incorporation of carbon leads to a reduction of the background electron co...

    U. Birkle, M. Fehrer, V. Kirchner, S. Einfeldt, D. Hommel… in MRS Online Proceedings Library (2011)

  4. No Access

    Article

    Statistical Analysis of Local Composition and Luminescence in InGaN Grown by Molecular Beam Epitaxy

    InGaN layers grown by molecular beam epitaxy are investigated in terms of their compositional homogeneity using transmission electron microscopy and cathodoluminescence spectroscopy performed with high spatial...

    S. Einfeldt, T. Böttcher, D. Hommel, H. Selke… in MRS Online Proceedings Library (2011)

  5. No Access

    Article

    Influence of Do** on the Lattice Dynamics of Gallium Nitride

    We present results of Raman-scattering experiments on GaN doped with Si, C, and Mg, respectively, grown by molecular beam epitaxy (MBE). The influence of the different dopants on strain and free-carrier concen...

    A. Kaschner, H. Siegle, A. Hoffmann, C. Thomsen… in MRS Online Proceedings Library (2011)

  6. No Access

    Article

    Compositional Fluctuations in AlxGa1-xN Layers grown on 6H-SiC (0001) by Metal Organic Vapor Phase Epitaxy

    The microstructural evolution of AlxGa1-xN films grown by metalorganic vapor phase epitaxy on 6H-SiC (0001) was studied by means of X-ray diffraction, atomic force microscopy and transmission electron microscopy ...

    R. Kröger, S. Einfeldt, Z. J. Reitmeier, R. Chierchia… in MRS Online Proceedings Library (2011)

  7. No Access

    Article

    Investigation of Green Emitting Monolithic II-VI Vertical Cavity Surface Emitting Laser

    In this paper, we are investigating the growth of a ZnSe based vertical cavity surface emitting laser (VCSEL). Undoped and p-type doped distributed Bragg reflectors (DBRs) with reflectivities exceeding 99% hav...

    C. Kruse, G. Alexe, R. Kröger, M. Klude, H. Heinke… in MRS Online Proceedings Library (2011)

  8. Article

    Open Access

    From serological surveillance to the identification of native human cases of hantavirus pulmonary syndrome in French Guiana

    S Matheus, F Djossou, D Moua, D Hommel, P Dussart, B de Thoisy… in BMC Proceedings (2011)

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  9. No Access

    Article

    Temperature dependence of radiative recombination in CdSe quantum dots with enhanced confinement

    We studied in details the recombination dynamics and its temperature dependence in epitaxially grown neutral CdSe/ZnSSe quantum dots with additional wide-band gap MgS barriers. Such design allows to preserve a...

    S. V. Zaitsev, T. Kümmell, G. Bacher, D. Hommel in JETP Letters (2010)

  10. No Access

    Article

    Direct observation of correlations between individual photon emission events of a microcavity laser

    Coherent light emission in lasers is reflected in a change of the photon statistics. Here Wiersig et al. demonstrate a streak camera technique with sufficient time resolution to probe the dynamical evolution of c...

    J. Wiersig, C. Gies, F. Jahnke, M. Aßmann, T. Berstermann, M. Bayer, C. Kistner… in Nature (2009)

  11. No Access

    Chapter and Conference Paper

    TEM analyses of microstructure and composition of AlxGa1−xN/GaN distributed Bragg reflectors

    In this work we analyse the microstructure as well as layer thicknesses and Al concentration of AlxGa1−xN/GaN distributed Bragg reflectors (DBRs) by transmission electron microscopy. To gain a high reflectivity o...

    A. Pretorius, A. Rosenauer, T. Aschenbrenner… in EMC 2008 14th European Microscopy Congress… (2008)

  12. No Access

    Chapter and Conference Paper

    Concentration Evaluation in Nanometre-Sized In x Ga1-x N Islands Using Transmission Electron Microscopy

    In this work the indium concentration of uncapped InGaN samples is measured by three different transmission electron microscopy approaches which are based on measurement of local lattice plane distances. In th...

    A Pretorius, K Müller, T Yamaguchi, R Kröger… in Microscopy of Semiconducting Materials 2007 (2008)

  13. No Access

    Chapter

    Wide-Bandgap Quantum Dot Based Microcavity VCSEL Structures

    In this contribution we report on the optical properties of planar and pillar structured GaN- and ZnSe-based monolithic microcavities. These structures reveal three-dimensional confined optical modes with high...

    K. Sebald, H. Lohmeyer, J. Gutowski, C. Kruse… in Advances in Solid State Physics (2008)

  14. No Access

    Article

    Spatially Resolved Characterization of Plastic Deformation Induced by Focused-Ion Beam Processing in Structured InGaN/GaN Layers

    In this study the results of polychromatic X-ray microbeam analysis (PXM) of the structural changes caused by FIB in nitride heterostructures are presented and discussed in connection with micro-photoluminesce...

    R. Barabash, G. Ice, R. Kroger, H. Lohmeyer, K. Sebald… in MRS Online Proceedings Library (2007)

  15. No Access

    Article

    Spatially Resolved Characterization of Microstructure, Defects and Tilts in GaN Layers Grown on Si(111) Substrates by Maskless Cantilever Epitaxy

    The spatially resolved distribution of strain, misfit and threading dislocations, and crystallographic orientation in uncoalesced GaN layers grown on Si(111) substrates by maskless cantilever epitaxy was studi...

    R. I. Barabash, C. Roder, G. E. Ice, S. Einfeldt… in MRS Online Proceedings Library (2006)

  16. No Access

    Article

    Characterization of Stress Relaxation, Dislocations and Crystallographic Tilt Via X-ray Microdiffraction in GaN (0001) Layers Grown by Maskless Pendeo-Epitaxy

    Intrinsic stresses due to lattice mismatch and high densities of threading dislocations and extrinsic stresses resulting from the mismatch in the coefficients of thermal expansion are present in almost all III...

    R.I Barabash, G. E. Ice, W. Liu, S. Einfeldt, D. Hommel… in MRS Online Proceedings Library (2006)

  17. No Access

    Article

    Comparative investigation of quantum-dot-like localization centers in InGaN quantum well and quantum dot structures

    We present comparative micro-photoluminescence measurements on InGaN/GaN quantum well and quantum dot samples. Single sharp emission lines were investigated for both kinds of samples as a function of temperatu...

    K. Sebald, H. Lohmeyer, J. Gutowski, T. Yamaguchi… in MRS Online Proceedings Library (2005)

  18. No Access

    Article

    X-ray standing wave investigations of Si dopant incorporation in GaN

    The synchrotron radiation technique of x-ray standing waves (XSW), which allows to directly obtain structural and element-specific data, was successfully used for the investigation of the dopant site distribut...

    M. Siebert, Th. Schmidt, J. I. Flege, J. Zegenhagen… in MRS Online Proceedings Library (2005)

  19. No Access

    Article

    Anti-diffusion barriers for gold-based metallization to GaN

    We propose a new metallization scheme to p-GaN, where thin-film transition metal nitrides have been applied to improve thermal stability of gold-based metallization. In this metallization scheme the Pd/Au bila...

    A. Piotrowska, E. Kaminska, M. Guziewicz, E. Dynowska… in MRS Online Proceedings Library (2005)

  20. No Access

    Article

    Resonant modes in monolithic nitride pillar microcavities

    GaN-based airpost pillar microcavities are realized by focused-ion beam etching starting from an all-epitaxially grown vertical-cavity surface-emitting laser structure. Pillar diameters below 1 μm are well co...

    H. Lohmeyer, K. Sebald, J. Gutowski… in The European Physical Journal B - Condense… (2005)

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