Optical study of direct interface in InP/InAlAs/InP double heterostructures grown by MOCVD

A photoluminescence (PL) study of direct interface (InAlAs/InP) properties in InP/InAlAs heterostructures grown by metal–organic chemical vapor deposition on (1 0 0) InP substrate has been carried out. At low temperature, a broad PL band View the MathML source has been observed around View the MathML source which is attributed to direct interface recombination. This PL line was strongly blue shifted (View the MathML source over three decades) when increasing the excitation density, and no saturation of the associated PL intensity was observed. This is the characteristic of type II or mixed type I–II transition.