@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{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{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}
}
@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{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{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}
}
@inproceedings{BicknellTassiusSchollBeckeretal.1992,
  author    = {Bicknell-Tassius, R. N. and Scholl, S. and Becker, Charles R. and Landwehr, G.},
  title     = {High magnetic field transport in II-VI heterostructures},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37797},
  year      = {1992},
  abstract  = {In the present work we report the results of magneto-transport measurements on some Hg-based li-VI semiconductor epitaxiallayers grown by molecular beam epitaxy. The transport measurement were carried out at temperatures in the range 0.4 - 4.2 K in magnetic fields up to 10.0 T. Further, we point out the necessity of using multicarrier models for data interpretation and show finally some Shubnikov-de-Haas results on sampies with high mobility carners.},
  language  = {en}
}
@article{WuBeckerWaagetal.1991,
  author    = {Wu, Y.S. and Becker, Charles R. and Waag, A. and Kraus, M. M. and Bicknell-Tassius, R. N. and Landwehr, G.},
  title     = {Correlation of the Cd-to-Te ratio on CdTe surfaces with the surface structure},
  isbn      = {0163-1829},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37789},
  year      = {1991},
  abstract  = {We report here that reconstruction on (100), (1lIlA, and (1l1lB CdTe surfaces is either C(2X2), (2X2), and (l X I) or (2X I), (l X I), and (l X I) when they are Cd or Te stabilized, respectively. There is a mixed region between Cd and Te stabilization in which the reflected high-energy electron-diffraction (RHEED) patterns contain characteristics of both Cd- and Te-stabilized surfaces. We have also found that the Cd-to-Te ratio of the x-ray photoelectron intensities of their 3d\(_{3/ 2}\) core levels is about 20\% larger for a Cd-stabilized (1lIlA, (1lIlB, or (100) CdTe surface than for a Te-stabilized one. According to a simple model calculation, which was normalized by means of the photoelectron intensity ratio of a Cd-stabilized (lll)A and aTe-stabilized (1l1lB CdTe surface, the experimental data for CdTe surfaces can be explained by a linear dependence of the photoelectron-intensity ratio on the fraction of Cd in the uppermost monatomic layer. This surface composition can be correlated with the surface structure, i.e., the corresponding RHEED patterns. This correlation can in turn be employed to determine Te and Cd evaporation rates. The Te reevaporation rate is increasingly slower for the Te-stabilized (Ill) A, (l1l)B, and (100) surfaces, while the opposite is true for Cd from Cd-stabilized (Ill) A and (Ill)B surfaces. In addition, Te is much more easily evaporated from all the investigated surfaces than is Cd, if the substrate is kept at normal molecular-beam-epitaxy growth temperatures ranging from 2oo·C to 300 ·C.},
  subject      = {Festk{\"o}rperphysik},
  language  = {en}
}
@article{QiuHeLietal.1993,
  author    = {Qiu, Yueming and He, Li and Li, Jie and Yuan, Shixin and Becker, Charles R. and Landwehr, G.},
  title     = {Infrared photoconductor fabricated with HgTe/CdTe superlattice grown by molecular beam epitaxy},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-37772},
  year      = {1993},
  abstract  = {An infrared photoconductor fabricated with a HgTe/CdTe superlattice grown on a GaAs substrate by molecular beam epitaxy is described here for the first time. The growth procedure, device fabrication, and measurement results are described. The results show that the device has relatively high uniformity and 1000 K black-body detectivity 2.4 X 10\(^9\) cm Hz\(^{1/2}\) W\(^{-1}\) . The photoconductivity decay method was used for determining carrier lifetime of the HgTe/CdTe superlattice, the measured lifetime is 12\(\mu\)s at 77 K, which is the longest lifetime ever reported for HgTe/CdTe superlattices and we believe that the increase of lifetime is mainly due to the reduction of dimensions.},
  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}
}