Pressure dependence of the optical absorption edge in Cd_1-xMn_xTe

Abstract

For the Mn-substituted CdTe semiconductors, the anomaly of the pressure coefficient of the optical absorption edge at about 2.0-2.3 eV with large concentration values, x, is studied by using the method of linear combinations of atomic orbitals. Results show that at the optical absorption edge, the p-d excitations may occur at higher Mn-concentrations and the pressure behaviour has a negative pressure effect similar to the Mn intra-d excitations. The physical reason for the negative pressure effect of the p-d transition is discussed and the numerically calculated result of the pressure coefficient for Cd0.5Mn0.5Te is found to be in excellent agreement with the experimental data.

The Numerical Solution of the Nonlinear Poisson-Boltzmann Equation Under the Anisotropic Boundary Condition for Colloidal Plasmas

“…This means that the field begins to have an opposite direction when | C |> 1.1, i.e., there is an attractive region when the corresponding dipole part of the potential dominates over the monopole part. This explanation agrees with the notion that the interaction energy transits from repulsion to attraction due to the interaction of effective dipoles [14] . It is worth to note that there is a potential well behind the macroparticle when C = −1.1, as shown in Fig.…”

“…In contrast, GRIE et al [10,11] and Tong Penger's group [12,13] discovered experimentally that there was a strong attractive force between the charged colloidal spheres. LIAN et al [14] found that a long-range attraction emerged in two like-charged colloid spheres with a nonuniform surface charge distribution in the confined system and suggested that the interaction energy between two spheres came from the competition of the attractive interaction between effective dipoles and repulsion interaction between two effective charges. In colloidal plasmas, to study the attractive interaction, many works mainly concentrated on the interaction energy between two like-charged colloid spheres, but neglected the influences of the surrounding macroparticles.…”