High temperature Hall-effect investigations were used to study the change of the concentration and mobility of charge-carriers in Cd0.85Mn0.10Zn0.05Te and Cd0.85Mn0.10Zn0.05Te: In crystals grown by the vertical Bridgman technique. The Cd0.85Mn0.10Zn0.05Te and Cd0.85Mn0.10Zn0.05Te: In samples are characterized by optical and electrical measurements, and by IR-microscopy. We determined that the value of band gap increase with the Mn and Zn amount increasing in the Cd1-x-yMnxZnyTe crystals. We also show that after the high-temperature Hall-effect measurements performed under Cd overpressure the both crystals resistivity increase from 104 Ohm×cm to 106 Ohm×cm, and amount and size of Te inclusions decrease. According to the results of the high temperature Hall-effect investigations the temperatures and Cd vapor pressures intervals were established in which Indium plays major role and controls the concentration of charge carriers.
In this paper, correlation between CMZT melt state and structure properties of crystals, grown by vertical Bridgman method, was investigated. The Cd0.9-xMnxZn0.1Te crystals with various Mn composition (x = 0.1; 0.2) were grown by two-step preparation method from high purity elemental components. We have conducted series of crystal growth runs with different melt superheating degree over the alloys melting temperature. As a result, we have got the ingots with various crystalline structures and properties. It was concluded that worth crystalline structure had the bulks which were grown from the melt with lowest superheating degree. We have determined also that band gap rose (from 1.67 at x=0.1 to 1.79 eV at x=0.2) with Mn content increasing.
Using the differential thermal analysis we investigated parameters of melting and crystallization processes of the CdTe based phase in CdTe-Al system near the CdTe side (CdTe + 2 mol. % Al, CdTe + 4 mol. % Al and CdTe + 6 mol. % Al). Varying temperatures of the melts intermediate isothermal holding for 10-, 30- and 60 minutes during their heating up to 1423 K we determined conditions of the melts full homogenization. It was concluded about change of the CdTe phase melting mechanism with Al content rise.
We detailed, by differential thermal analysis (DTA), some features of the melting- and cooling-processes in
CdTe-ZnTe with a ZnTe content of up to 10 mol. % by evaluating their influence on the parameters of melting and
crystallization. We focused on the heating/cooling rate, the melt's maximum temperature, and the duration of holding the
melt at this maximum. Using the interrelationship in the Kissinger equation, ln(V h/(TLmp)2) = A+ Ea/(R TLmp), between
the heating rate (V h) and the maximal temperature of the melting process's endothermic effect ( TLmp ), we estimated the
melting process's activation energy (Ea). In addition, we studied the temperature dependencies of the volume fraction of
the solid phase that remained in the CdTe-ZnTe melts, and the influence of the melt's "thermal prehistory" on the
parameters of its crystallization parameters. Due to these studies we assessed the temperature intervals of the solid
phases' existence and the temperature intervals of melts' crystallization.