Some general features of the behaviour of Cu, Zn, Bi, and Mn impurities in CdSiP2 and CdP2 crystals are studied by analyzing electron beam‐excited luminescence spectra measured in a temperature range of 6 to 300 K, as well as by determining their electrical parameters. The impurities are established to substitute mainly the cadmium in the crystalline lattice and to promote the formation of complexes of defects, which are radiative recombination centers. Cadmium vacancies as well participate in the defect complex formation processes. A radiation ascribed to interstitial cadmium‐type defects, is discovered in CdSiP2 crystals.

An investigation is made of the Cathodoluminescence spectra of CdP2 crystals in the temperature range 6 to 300 K. A pulsing beam of high energy electrons (40 kV) is used in the experiment. The samples investigated are undoped, heat annealed in vacuum or saturated vapours of cadimum, and also doped with As an Bi, elements isoelectronic to phosphorus. The experimental results show that the fine structure present in the higher energy wing (2.02 to 2.14 eV) depends on the concentration of the uncontrolled nitrogen impurity in CdP2. Atoms of nitrogen give rise to exciton‐impurity complexes, leading to intense narrow peaks in the spectrum of Cathodoluminescence. Their location and nature are shown in a table.

Spectral dependences of the gyration tensor components gll, gas, refraction indices and birefringence of tetragonal CdP, are investigated a t 300 I<. The optical activity of the crystal is found to be determined by both the crystal and the molecular contributions, the latter being due to the distortion of the tetrahedral symmetry of the structural elements. The dispersion of the refractive indices is discussed on the basis of a single-effective-oscillator model. The ionicity of CdP, is equal to 0.5B and is close to the values of AIIBVI compounds and the ionicity of Cd-P bond in AI1BrVCT semiconductors. The dispersion of the spectroscopic properties of CdP, is concluded to be mainly determined by the Cd-P bound. HemB Tnna AIIBVI, a TaKme c~m e i i Cd-P B nonynpoBonmKax AIIBIVCZ. ~~K J I I~Y~~T C H