Growth and characterization of beryllium-based II–VI compounds

Abstract

We report on the growth and characterization of beryllium–chalcogenide layers prepared on GaAs (100) by molecular beam epitaxy. Be- and Te-terminated BeTe surfaces show (4×1) and (2×1) reconstructions, respectively. The stability of each surface is investigated by reflection high energy electron diffraction as a function of substrate temperature. The dependence of growth rate of BeTe on growth temperature and Be cell temperature is investigated. The best full width at half maximum (FWHM) of a (400) x-ray rocking curve of BeTe is 78 arcsec. The dependence of the ZnBeSe energy gap on Be composition is obtained by four-crystal x-ray diffraction (XRD) and low temperature photoluminescence measurements. The energy gap of Zn1−xBexSe varies as Eg=0.0107x+2.790 (eV) for small Be composition (x<0.25) at 77 K. Lattice-matched ZnBeSe (Eg=2.82 eV) and ZnMgBeSe (Eg=2.975 eV) layers show narrower XRD peaks, the FWHM values of which are 64 and 21 arcsec, respectively. The variation of FWHM of x-ray rocking curve due to lattice misfit is investigated for ZnMgBeSe quaternaries with various lattice misfits extending from compressive to tensile strain. The FWHM value under compressive strain increases more steeply with lattice misfit than that under tensile strain.

Chemical Surface Analysis by Raman Spectroscopy Utilizing Dimer Vibrations

“…This arrangement corresponds to a 4 1 surface reconstruction as reported in Refs. [11,12], which should be confirmed in LEED when occurring over sufficiently extended coherent regions. However, the LEED pattern of these Be-rich surfaces is rather diffuse and does not allow the unambiguous 4 1 identification.…”

“…From RHEED a 4 1 reconstruction is reported for the Berich surface [11,12], which may be accompanied by a transition between 4 1 and 3 1 [12]. However, a modeling of the unit cell is lacking until now.…”

First-principles calculations of structural, electronic, and thermodynamic properties of ZnO 1− x S x alloys

“…[1][2][3][4] They have also been found to have applications in short wave length optoelectronic components in laser diodes (LDs) and light emitting diodes (LEDs). [5] Therefore, wide band gap II-VI semiconductors have appeared as research candidates in theoretical and experimental fields. [6] Zinc oxide, a wide gap semiconductor, has potential applications in geophysical and fundamental material physics due to its stability at ambient pressure.…”

HgCdTe on Si: Present status and novel buffer layer concepts

“…886 Golding, Holland, Kim, Dinan, Almeida, Arias, Bajaj, Shih, and Kirk strating that a ternary-compound BeSe x Te (1-x) could be grown lattice-matched on silicon at a specific composition, as shown in Fig. [24][25][26] These groups have explored binary, ternary, and quaternary compounds, such as BeTe, BeMgTe, BeMgZnSe, BeZnSeTe, BeZnCdSe, and ZnSe-BeTe superlattices on GaAs substrates. 22,23 Groups in Germany, France, and Japan have also recently pursued growth of beryllium chalcogenides on other compound semiconductor substrates of varied interest.…”