OPTICAL-PROPERTIES OF ATOMIC LAYER GROWN INAS ALSB QUANTUM-WELL STRUCTURES BY GAS-SOURCE MIGRATION-ENHANCED EPITAXY/

InAs/AlSb quantum well (QW) structures with InAs buffer layers are gro wn on (001) GaSb substrates by gas source MEE (migration enhanced epit axy). PL (photoluminescence) measurements show that the optical proper ties of InAs/AlSb QWs strongly depend on the shutter sequence at the i nterfaces and therefore the type of the heterointerfaces (InSb-type, A lAs-type). 77 K PL intensity from the QWs with InSb-type interfaces is much stronger than that with AlAs-type interfaces. Furthermore, the t emperature variation of the former is much weaker than that of the lat ter. However, the 4.2 K PL intensity is on nearly the same level for b oth types. PL peak energy is also dependent on the heterointerface typ es, which is explained by taking account of the potential profiles at the interfaces; the InSb-type interfaces increase the effective thickn ess of the InAs wells. These optical properties are different from tho se of the InAs/AlSb QWs with AlSb buffer layers. The origin of the dif ference is discussed.