Peltier-induced LPE and composition stabilization of GaAlAs

Abstract

Peltier-induced liquid-phase epitaxial growth of Ga1−xAlxAs (0.1⩽x⩽0.3) was carried out at constant temperature with the dc as the sole driving force and controlling element of the growth. Electric currents of 10–30 A/cm2 were passed through the solid-liquid (S-L) interface (which acts as a Peltier junction) thereby cooling this interface and causing growth. The growth rate is linearly proportional to the current level. GaAlAs layers of 15–58 μm thickness were grown from relatively small melts (∼5 g) at several temperatures in the range 600–850 °C. Photoluminescence microanalysis of the layers showed that the aluminum composition was remarkably uniform throughout the total layer thickness. In all cases, the variation of the aluminum concentration (x) was observed to be ±0.005 or less.