Acceptors in Cd1−x MnxTe (x<0.1)

Abstract

Self-focusing of 1aser beams is observed in Cd0.5Mn 0. 5 Τe at room temperature. The far-field patterns of laser beam after passing through the cad-mium manganese telluride crystal are investigated. The values of focal length as well as the absorption coefficient were measured as a function of intensity of laser radiation. From these measurements the values of nonlinear refrac-tive index for Cd0.5Mn0.5Te are determined. The results indicate that the self-focusing observed in Cd 1-x ΜnxTe is due to a thermally induced change in refractive index. PACS numbers: 42.65.Jx A well-known third-order nonlinear optical effect of great interest is the phenomenon of self-focusing of light. Self-focusing may occur when the refractive index of the nonlinear medium increases with the beam intensity, n = n0 + Δn, where Δn is the laser induced refractive index. and n 0 is the index of refraction for low intensity light. One of the most important physical mechanism responsible for Δn in semi-conduction is heating by CW laser beam with photon energies close to the band gap energy. It leads to dispersive nonlinearity induced by a shift of the band gap energy. In case of a laser beam with a Gaussian transverse profile propagating into the semiconductor with dn/dT > 0, the central part of the beam sees a larger refractive index than the edge. Consequently, the beam is focused by itself. Dis-persive nonlinearisty induced by a thermal shift of the band gap energy has been studied in several semiconductors [1]. In this paper the investigations of self-focusing of laser beam in Cd0.5Mn0.5Te is reported. It should be noticed that in Cd1-xMnxTe crystals with x > 0.5 the fundamental absorption is obscured by transitions within Mn++ ions [2]: Therefore,

HgCdMnZnTe: new material for IR photoelectronics

“…This fact, as well as the increase in crystal grain size and the reduction of their disorientation, as found from X-ray crystal investigations, allows the assertion that introducing up to 10% of manganese into Hg 1−x Cd x Te crystal leads to crystal lattice stabilization of mercury-containing solid solution. This is somewhat contradictory to conclusions in [13] on the destabilizing effect of manganese on crystal properties of wide-band mercury-free CdMnTe materials, however, these are also inconsistent with the results in [14,15] demonstrating a considerable improvement in structural and mechanical properties of CdMnTe crystals with manganese content 1-10% as compared to CdTe.…”

Distribution of components in epitaxial graded band gap heterostructures Cd(Mn,Zn)Te – Cd(Mn,Zn)HgTe and their photoelectrical properties

“…It is known that presence of smaller atoms in the crystal lattice may facilitate relaxation of elastic deformations and improvement of the structural perfection [9]. Particularly, Cd 1y Zn y Te (y = 24 %) and Cd 1-y Mn y Te (ó < 10%) are known to exhibit the block-type structure to a lesser extent than CdTe [10,11]. In order to improve the structural perfection and recombination parameters of epitaxial CdHgTe films, particularly near the metallurgical interface, we used in this work ternary compounds Cd 1-y Zn y Te and Cd 1-y Mn y Te (ó < 10 %) as substrates for growth of graded-gap films.…”

“…Microinclusions of MnTe 2 are quite likely to appear in the presence of excess Òå in the material. The effect of Mn-enriched inclusions on the electrical properties of CdMnTe was reported in [11].…”

Electro-Physical Properties of Ge-doped Cd1-xMnxTe (x < 0.1) Crystals

“…To determine the ionization energy (ε A ) of acceptor A, which controls p-conductivity in Cd(Mn)Te-Ge crystals, the results of Fig. 3 were analyzed using a compensated semiconductor model that determines the position of the donor or acceptor levels relative to the edges of the corresponding bands at 0 K. For calculations, the values of the effective masses of states' densities m n * = 0.11m 0 , m p * = 0.63m 0 for pure cadmium telluride [28] and the values of the band gap width for Cd(Mn)Te at 0 K and at 300 K, were used in the works [29,30]. A linear dependence of ε A on the content Mn (Fig.…”