Electrical properties of CdTe:P single crystals at low and high temperatures

Abstract

High-temperature (470-1170 K) properties of CdTe:P single crystals, grown by Bridgman technique, with an initial concentration of impurities in the melt 1x10(19) at/cm(3), were investigated by measuring of the Hall effect. Experimental results indicate that up to the temperature of similar to 700 K samples had p-type conductivity and above similar to 940 K - n-type one. Character of isothermal dependences of Hall constant strongly differs from the dependence of the undoped material due to the influence of impurities. Acceptor effect of phosphorus is observed up to 1170 K, it shows a high content of acceptor impurity form (P-Te). The low-temperature electric measurements data confirm the fact of phosphorus high solubility in CdTe. The results of IR microscopy indicate that the introduction of phosphorus into CdTe crystal resulted in almost complete eliminatio n of second phase inclusions with size >= 1 mu m, which are usually present in such material.