A. Szadkowski

Parameters of substrates-single crystals of ZnTe and Cd1-xZnxTe (x < 0.25), obtained by physical vapor transport technique (PVT)

Abstract It is shown that very high quality (in particular – very good real crystal structure) of the single crystals of ZnTe and Cd 1− x Zn x Te, intended to be substrates for MBE and other techniques of epitaxy, can be reached by an optimized physical vapor transport (PVT) technique. The obtained crystals are twin-free, the narrowness of the rocking curve nearly reaches the theoretical limit and the density of dislocations is low. The results of characterization of the crystals are presented.

Influence of annealing on tellurium precipitates in (Cd,Mn)Te:V crystals

The authors believe that (Cd,Mn)Te can be used as a material for gamma- and X-ray detectors [1]. The investigations are concentrated on producing, by Bridgman method, of high quality (Cd,Mn)Te crystals with high resistivity (109 Ωcm).

Low defect density, substrate quality crystals of the wide-gap II–VI compounds, obtained by physical vapour transport technique (PVT)

Abstract It is demonstrated that substrate quality, 1 in. size single crystals of the wide-gap II–VI semiconductors: ZnSe, Zn(Se,S), ZnTe and (Cd,Zn)Te can be obtained by a simple, horizontal, low temperature, physical vapour transport (PVT) technique. The results of the characterization of the obtained crystals are presented.

Technology and Characterization of Single‐Crystalline Substrates Made of ZnSe‐Based Wide‐Gap II–VI Semiconductor Compounds

Detrimental role of traces of oxygen in the growth process of the ZnSe-based wide-gap II-VI semiconductor crystals is emphasized. Adhesion, enhanced by the presence of oxygen, of the growing crystal to the walls of the quartz ampoule promotes generation of twinning and dislocations. The technology of the substrate-quality crystals, which ensures nearly complete removal of oxygen, is described. The results of characterization of the obtained large (25 mm diameter), twin-free single crystals of ZnSe, and substrate plates are presented.

(Cd,Mn)Te Crystal Plates for Radiation Detectors: Electrical Contacts and Surface Passivation

The development of a reliable technique for making good electrical contacts to semi-insulating (Cd,Mn)Te monocrystalline plates meant for x- and gamma radiation detectors, a technique of crystal surface preparation and a technique of passivation of the surfaces between electrodes were the main objectives of the studies. The investigations of the electrical contacts were focused on the amorphous/nanocrystalline contact layers. The effects of passivation of the inter-electrode surfaces on the magnitude of the surface leakage currents were studied.

Semi-insulating and n-type substrates quality ZnSe and ZnSe1 − xSx (x < 0.15) produced by low temperature physical vapour transport

We employed the low temperature physical vapour transport (PVT) method to grow high quality, large (25 mm in diameter) bulk crystals of ZnSe and ZnSe1 − xSx (x < 0.15). Characterization of the obtained crystals was performed by means of X-ray diffraction. X-ray full with half maximum (FWHM) rocking curves and the energy dispersive X-ray fluorescence (EDXRF) spectrometry. Optical properties were determined from the low temperature near-band-edge photoluminescence and reflection measurements. The photoluminescence was studied also in the conditions of high excitation intensity. A superlinear relation between log(luminescence intensity) and log(excitation intensity) and narrowing of the luminescence line have been observed, indicating stimulated emission phenomena.

Technique of making good electrical contacts to high resistivity (Cd,Mn) Te crystals

The authors believe that semiinsulating (Cd,Mn)Te crystals can successfully replace the commonly used (Cd,Zn)Te crystals as a material for manufacturing large-area X- and Gamma- ray detectors. Good quality, high-resistivity (10⁹ ÷ 10¹⁰ Ω·cm) crystals of (Cd,Mn)Te:V are grown by the Bridgeman method. Doping (≈1016 cm⁻³) with vanadium, which acts as a compensating dopant, and special annealing in cadmium vapours, which reduces the number of cadmium vacancies existing in the crystal after the growth, ensure high resistivity of the crystals.