Evidence of interface-induced persistent photoconductivity in InP/In{sub 0.53}Ga{sub 0.47}As/InP double heterostructures grown by molecular-beam epitaxy

The impact of interface switching sequences on interface quality and minority carrier recombination in In{sub 0.53}Ga{sub 0.47}As/InP double heterostructure (DH) grown by solid-source molecular-beam epitaxy (MBE) was studied. As{sub 2} exposure at the lower In{sub 0.53}Ga{sub 0.47}As/InP interface prior to In{sub 0.53}Ga{sub 0.47}As growth was found to cause enhanced As diffusion into the underlying InP that correlates with steadily increased photoconductive decay (PCD) lifetimes beyond the theoretical radiative and Auger limit. Low-temperature PCD measurements reveal that a persistent photoconductivity (PPC) process is responsible for the high 'apparent' lifetimes. The PPC effect increases monotonically with As{sub 2} exposure on the InP surface, implying the involvement of interfacial defects in the carrier recombination dynamics of In{sub 0.53}Ga{sub 0.47}As/InP DHs grown by MBE.