Anisotropic interfacial strain in InP/InGaAs/InP quantum wells studied using degree of polarization of photoluminescence

Room-temperature, polarization-resolved photoluminescence from a (001) surface has been used to investigate InP/InGaAs/InP quantum wells grown by gas source molecular beam epitaxy. The degree of polarization of photoluminescence from a (001) surface, DOP001, is a direct measure of the anisotropy of polarization of luminescence between [110] and [11̄ 0] directions. DOP001 is observed to be strongly dependent on the quantum well thickness, composition (strain), and the gas switching time at the growth-interrupted interface. Results show that the anisotropy of polarization may be due to an effect of an anisotropic strain field that is associated with strained bonds at the interfaces of the quantum well.