Physico-chemical properties of Ga and In dopants during liquid phase epitaxy of CdxHg1-xTe

This work deals with the study by means of radioactive tracers autoradiography, as well as measuring of galvanomagnetic properties, of Ga and In doping of epitaxial CdxHg1-xTe layers during their crystallization from a Te-rich melt. Ga and In were introduced in the form of Ga-72 and In-114 master alloys with Te. The effective distribution coefficients of Ga and In during the crystallization of the CdxHg1-xTe solid solutions with x = 0.20 to 0.23 were determined by cooling the Te-base melt to 515-470 degrees C. Depending on the concentration of the dopants and the time-temperature conditions of CdxHg1-xTe growth, these ratios for Ga and In were 1.5-2.0 and 1.0-1.5, respectively. The electrical activity of Ga and In was determined after annealing of the CdxHg1-xTe layers in saturated Hg vapor at 270-300 degrees C. In doping of the epitaxial layers to (3-8) x 10(14) cm(-3) with subsequent annealing in saturated Hg vapor at similar to 270 degrees C increases the carrier Lifetime approximately by a factor of two as compared with the undoped material annealed under the same conditions.