We have implanted Hg0.3Cd0.7Te compounds with various ions (aluminium, xenon and krypton) at different substrate temperatures (300 and 15 K). Implantations were performed with impinging ions having a kinetic energy in the range 60–320 keV, their fluence varying between 5 × 1011 and 5 × 1014 ionscm−2. Samples have been characterized before and after annealing (300° C, 2 h) by SIMS, EBIC, TEM, RBS and differential Hall effect. The overall result is that the p/n transformation is linked to defects induced during implantation. The saturation in the sheet carrier concentration nsfor φ > 5 × 1013 Alcm−2 could be caused by fact that the recombination volume has then been reached.

p-type crystals of the ternary compounds Hg1−xCdxTe have been irradiated with high-energy ions and electrons. Electron-beam-induced current signals on xenon- and krypton-irradiated Hg1−xCdxTe show that n-type conversion, occurring all along the ion path, is related to the presence of mercury atoms. Resistivity and Hall measurements on carbon-, oxygen-, xenon- and electron-irradiated Hg0.8Cd0.2Te crystals allow us to determine the effective cross section for atomic displacement. We observe, for electron-irradiated samples, a saturation in carrier concentration interpreted as the pinning of the Fermi level at a resonant donor state 370 meV above the bottom of the conduction band. Comparison between ion and electron irradiations shows that electrically active produced defects are mainly due to atomic collisions. Additional reduction of defect production efficiency for xenon ions may be the onset of some energy transfer from electronic loss to target atoms.

Cd x Hg1−xTe (0⩽x⩽1) single crystals were strained by microhardness and by constant strain rate uniaxial compression tests, in the temperature range 300 to 600 K. Hardness curves as function of temperature can be described by empirical relations. Stress-strain curves, relaxation tests and dislocation observations using transmission electron microscopy show that the deformation is controlled by a thermally activated Peierls mechanism. Moreover, dislocations are dissociated with a stacking fault energy which does not depend on thex composition.

Hgl-x Cdx Te is a good candidate for signal transmission through fiber optics for it has an adjustable direct band gap (x ~ 0.7 for silica glass and x~ 0.4 for fluorine glass). Photovoltaic detectors can be made by implantation on a p-type substrate. However the physical nature of the junction is not yet clearly understood. We implanted various ions (Al, Xe, Kr) at different energies, (60 3 keV to 320 keV) and temperatures (15 K, 300 K) in p-type bulk Hg 0.3 Cd 0.7 Te (p~ 1.5 x 10 16/cm3). From E.B.I.C. and differential Hall measurements, we conclude that Hg inferstitials should be the most realistic candidates as doping defects.

The intrinsic semiconductor alloy system Cdx Hgl-x Te is an important material for I.R detection. By changing the alloy composition x, the energy gap of Cdx Te can be varied and may be optimized for various wavelengths through the I.R spectrum. The most important wavelength ranges are the atmospheric windows 8-12 μ (x≈ 0,2) and 3-5 μ (x≈ 0,3) for thermal imaging and the 1,3-2,5 μ range (x ≈0,5 to 0,7) for optical fiber applications.

The Travelling Heater Method has been applied to the crystal growth of CdxHgl-xTe for infrared applications. The main characteristics and advantages of this method are presented with regard to the two most important metallurgical difficulties of CdxHgl-xTe : mercury pressure and phase segregation. Metallurgical and electrical properties of the ingots are presented.