ORDERING EFFECTS IN INGAP GAAS AND INGAASP/GAAS HETEROSTRUCTURES GROWN BY LP-MOVPE/

The cationic ordering in InGaP epilayers grown by low-pressure vapour phase epitaxy on GaAs substrates has been investigated by X-Pay diffra ction. The effects of both the substrate miscut and the doping with Si and Zn have been studied. It has been found that ordering effects occ ur inside relatively small domains on (1-11) and (-111) planes; howeve r, by increasing the miscut angle the domains of the first kind tend t o increase their dimensions, while the second ones tend to disappear. Moreover, doping with impurities substituting cations is seen to destr oy the order. Photoluminescence anomalies have been revealed and corre lated to the size and ordering degree of the ordered domain.