@article{BeckerHeEinfeldtetal.1993,
  author    = {Becker, Charles R. and He, L. and Einfeldt, S. and Wu, Y. S. and L{\´e}rondel, G. and Heinke, H. and Oehling, S. and Bicknell-Tassius, R. N. and Landwehr, G.},
  title     = {Molecular beam epitaxial growth and characterization of (100) HgSe on GaAs},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-50947},
  year      = {1993},
  abstract  = {In this paper, we present results on the first MBE growth of HgSe. The influence of the GaAs substrate temperature as well as the Hg and Se fluxes on the growth and the electrical properties has been investigated. It has been found that the growth rate is very low at substrate temperatures above 120°C. At 120°C and at lower temperatures, the growth rate is appreciably higher. The sticking coefficient of Se seems to depend inversely on the Hg/Se flux ratio. Epitaxial growth could be maintained at 70°C with Hg/Se flux ratios between lOO and ISO, and at 160°C between 280 and 450. The electron mobilities of these HgSe epilayers at room temperature decrease from a maximum value of 8.2 x 10^3 cm2 /V' s with increasing electron concentration. The concentration was found to be between 6xlO^17 and 1.6x10^19 cm- 3 at room temperature. Rocking curves from X-ray diffraction measurements of the better epilayers have a full width at half maximum of 5S0 arc sec.},
  subject      = {Physik},
  language  = {en}
}
@article{ToenniesBacherForcheletal.1994,
  author    = {T{\"o}nnies, D. and Bacher, G. and Forchel, Alfred and Waag, A. and Litz, Th. and Hommel, D. and Becker, Charles R. and Landwehr, G. and Heuken, M. and Scholl, M.},
  title     = {Optical study of interdiffusion in CdTe and ZnSe based quantum wells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37750},
  year      = {1994},
  abstract  = {No abstract available},
  language  = {en}
}
@article{BeckerLatussekHeinkeetal.1993,
  author    = {Becker, Charles, R. and Latussek, V. and Heinke, H. and Regnet, M. M. and Goschenhofer, F. and Einfeldt, S. and He, L. and Bangert, E. and Kraus, M. M. and Landwehr, G.},
  title     = {Molecular beam epitaxial growth and characterization of (001) Hg\(_{1-x}\) Cd\(_x\) Te-HgTe superlattices},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-50959},
  year      = {1993},
  abstract  = {The molecular beam epitaxially growth of (001) Hg\(_{1-x}\) Cd\(_z\) Te-HgTe superlattices has been systematically investigated. The well width as well as the period were determined directly by X-ray diffraction. This was accomphshed for the well width by exploiting the high reflectivity from HgTe and the low reflectivity from CdTe for the (002) Bragg reflection. Knowing the well and barrier thicknesses we have been able to set an upper limit on the aver~ge composition of the barriers, Xl, by annealing the superlattice and then measuring the composition of the. resultmg alloy. Xb was shown to decrease exponentially with decreasing barrier width. Xb is appreciably smaller m. narrow barriers due to the increased significance of interdiffusion in the Hg\(_{1-x}\)Cd\(_x\) Te/HgTe interface in narrow barriers. The experimentally determined optical absorption coefficient for these superlattices is compared WIth theoretical calculations. The absorption coefficient was determined from transmission and reflection spectra at 300, 77 and 5 K. Using the thickness and composition of the barriers and wells, and an interface width due to interdiffusion, the complex refractive index is calculated and compared with the experimental absorption coefficient. The envelope function method based on an 8 x 8 second order k . p band model was used to calculate the superlattice states. These results when inserted into Kubo's formula, yield the dynamic conductivity for interband transitions. The experimental and theoretical values for the absorption coefficient using no adjustable parameters are in good agreement for most of the investigated superlattices. Furthermore the agreement for the higher energetic interband transitions is much worse if values for the barrier composition, which are appreciably different than the experimentally determined values, are used. The infrared photoluminescence was investigated at temperatures from 4.2 to 300 K. Pronounced photoluminescence was observed for all superlattices in this temperature range.},
  subject      = {Physik},
  language  = {en}
}
@article{BeckerWuWaagetal.1991,
  author    = {Becker, Charles R. and Wu, Y. S. and Waag, A. and Kraus, M. M. and Landwehr, G.},
  title     = {The orientation independence of the CdTe-HgTe valence band offset as determined by x-ray photoelectron spectroscopy},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30784},
  year      = {1991},
  abstract  = {No abstract available},
  language  = {en}
}
@article{WaagHeinkeScholletal.1993,
  author    = {Waag, A. and Heinke, H. and Scholl, S. and Becker, Charles R. and Landwehr, G.},
  title     = {Growth of MgTe and Cd\(_{1-x}\)Mg\(_x\)Te thin films by molecular beam epitaxy},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37917},
  year      = {1993},
  abstract  = {We report on the growth of the compound semiconductor MgTe as weil as the ternary alloy Cd\(_{l-x}\)Mg, Te by molecular hcam cpitaxy. This is to our knowkdgc thc first time that this material has heen grown by any epitaxial technique. Bulk MgTe, which is hygroscopic, has a band gap of 3.0 eV and crystallizcs usually in thc wurtzite structure. Pseudomorphic films were grown on zincblende Cd Te suhstrates for a MgTe thickness helow a critical layer thickncss of approximately 500 nm. In addition, Cd\(_{l_x}\),Mg\(_x\)Te epilayers were grown with a Mg concentration between 0 and 68\%, which corresponds to a band gap betwcen 1.5 and 2.5 eV at room temperature. The crystalline quality of thc layers is comparabk to CdTc thin films as long as they are fully strained. The lauice constant of zincblende MgTe is slightly smaller than that of CdTe, and the lattice mismatch is as low as O.7\%. In addition highly n-type CdMgTe layers were fabricatcd by hromine doping. The tunability of the band gap as weil as the rather good laUice match with CdTc makes the matcrial interesting for optoelectronic device applications for the entire visible range.},
  language  = {en}
}
@article{HerrmannHappMoellmannetal.1993,
  author    = {Herrmann, K. H. and Happ, M. and M{\"o}llmann, K.-P. and Tomm, J. W. and Becker, Charles R. and Kraus, M. M. and Yuan, S. and Landwehr, G.},
  title     = {A new model for the absorption coefficient of narrow gap (Hg,Cd)Te that simultaneously considers band tails and band filling},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37894},
  year      = {1993},
  abstract  = {A semiempirical model is presented that correlates the broadening of the absorption edge with both transitions below the energy gap and with transitions by the Kane band model. This model correctly fits both the absorption and luminescence spectra of narrow-gap (Hg,Cd)Te samples that have been grown by the traveling heater method as well as by molecular-beam epitaxy. The accuracy of the band-gap determination is enhanced by this model.},
  language  = {en}
}
@article{WuBeckerWaagetal.1992,
  author    = {Wu, Y. S. and Becker, Charles R. and Waag, A. and Bicknell-Tassius, R. N. and Landwehr, G.},
  title     = {Thermal effects on (100) CdZnTe substrates as studied by x-ray photoelectron spectroscopy and reflection high energy electron diffraction},
  issn      = {0003-6951},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37801},
  year      = {1992},
  abstract  = {The influence of different CdZnTe substrate treatments prior to II-VI molecular beam epitaxial growth on surface stoichiometry, oxygen, and carbon contamination has been studied using x-ray photoelectron spectroscopy and reflection high energy electron diffraction. Heating the substrate at 300 °C can eliminate oxygen contamination, but cannot completely remove carbon from the surface. Heating at higher temperatures decreases the carbon contamination only slightly, while increasing the Zn-Cd ratio on the surface considerably. The magnitude of the latter effect is surprising and is crucial when one is using lattice matched CdZnTe (Zn 4\%) substrates.},
  language  = {en}
}
@article{WuBeckerWaagetal.1993,
  author    = {Wu, Y. S. and Becker, Charles R. and Waag, A. and von Schierstedt, K. and Bicknell-Tassius, R. N. and Landwehr, G.},
  title     = {Surface sublimation of zinc blende CdTe},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37829},
  year      = {1993},
  abstract  = {The surface sublimation of Cd and Te atoms from the zinc blende (111)A CdTe surface has been investigated in detail by reflection high energy electron diffraction and x-ray photoelectron spectroscopy. These experiments verify that Te is much easier to evaporate than Cd. The experimental value for the Te activation energy from a Te stabilized (111)A CdTe surface is 1.41 ±0.1O eV, which is apparently inconsistent with recent theoretical results.},
  language  = {en}
}
@article{HeBeckerBicknellTassiusetal.1993,
  author    = {He, L. and Becker, Charles R. and Bicknell-Tassius, R. N. and Scholl, S. and Landwehr, G.},
  title     = {Molecular beam epitaxial growth of (100) Hg\(_{0.8}\)Cd\(_{0.2}\)Te on Cd\(_{0.96}\)Zn\(_{0.04}\)Te},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-38044},
  year      = {1993},
  abstract  = {No abstract available},
  language  = {en}
}
@article{KrausBeckerScholletal.1993,
  author    = {Kraus, M. M. and Becker, Charles R. and Scholl, S. and Wu, Y. S. and Yuan, S. and Landwehr, G.},
  title     = {Infrared photoluminescence on molecular beam epitaxially grown Hg\(_{1-x}\)Cd\(_x\)Te layers},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-38053},
  year      = {1993},
  abstract  = {No abstract available},
  language  = {en}
}