Ordering InGaP epilayer directly grown on Ge substrate

• We study the CuPt ordering phase in InGaP grown on miscut Ge substrate.
• Transmission electron diffraction is used to study the ordering direction.
• Relation between ordering and miscut directions is determined.
• The ordering is further confirmed by photoluminescence and Raman scattering.

We report on the structural properties of ordering InGaP directly deposited on (001) Ge substrate by organometallic vapor phase epitaxy. The Ge substrate is 6° miscut towards (110). Results from transmission electron diffraction indicate the existence of CuPt-B ordering phase in the sample. The ordering direction is assigned to be [11¯1], which is perpendicular to the miscut direction of the Ge substrate. Because only one ordering phase is observed, no anti-phase domain exists in the sample. The order parameter determined from photoluminescence at room temperature is 0.492. Raman scattering was also used to analyze the ordering effect. A mode at 354 cm− 1 relevant to the ordering phase confirms that the CuPt-B ordering is along [11¯1].