Evidence of type-II band alignment at the ordered GaInP to GaAs heterointerface

Publisher Website
Google Scholar
Abstract
Interfacial characteristics of Ga0.51In0.49P/GaAs heterostructures grown by metal‐organic vapor‐phase epitaxy in the temperature range from 600 °C to 730 °C were studied. Photoluminescence (PL) measurements have been used for this purpose. A PL peak with an energy of about 1.425 eV (870 nm) was continuously observed in samples containing the GaInP‐to‐GaAs interface. Excitation power dependent PL measurements show that this peak belongs to an excitonic recombination. Furthermore, a strong blue‐shift of this PL‐peak energy was observed as the excitation power increased. We attribute the 870 nm peak to the radiative recombination of spatially separated electron‐hole pairs and suggest the type‐II band alignment at the ordered GaInP to GaAs heterointerface under growth conditions reported here. Further investigations using x‐ray diffraction measurements and simulations with dynamical theory show that the lower and upper interfaces are not equivalent. This explains the absence of type‐II transition in most GaAs‐to‐GaInP lower interfaces.