Phase equilibria and liquid-phase-epitaxy growth of PbSnSeTe lattice-matched to PbSe

Abstract

The phase equilibria data necessary for growing solid compounds of Pb1−xsSnxsSe1−ys Teys lattice matched to PbSe from melts consisting of (Pb1−xLSnxL)1−z (Se1−yLTeyL)z are presented. Liquidus data for values of xL from 0% to 40% and yL from 0% to 40% for temperatures between 450 and 540 °C are also presented. The influence of tellurium on the liquidus temperature is shown to be negligible at least for yL less than 40%. A crossover in the liquid-solid tie lines of tin, xs vs xL, for layers grown at 650 and 450 °C is observed at xL equal to 14%. The liquid-solid tie-line data for tellurium, ys vs yL, show a low segregation coefficient relative to selenium for yL less than 40%, thus explaining tellurium’s limited influence on the liquidus temperature. The lattice-matching conditions for xL =5%, 10%, and 20% are yL =16.4%, 25%, and 33.5%, respectively. A significant lattice-pulling effect is observed for the 5% tin case and is expected for the 10% and 20% tin cases. This effect, along with the low relative segregation coefficient for tellurium, makes it possible to easily grow lattice-matched layers of PbSnSeTe on PbSe by liquid phase epitaxy.