Investigation of the growth temperature of AlGaAs barrier layer on optical and crystal quality of InGaAs/AlGaAs multi-quantum wells and AlGaAs single layer grown by molecular beam epitaxy (MBE)

The effect of growth temperature on the crystal quality and optical properties of InGaAs/AlGaAs multiple quantum wells (MQWs) with AlGaAs barriers was studied. The AlGaAs layers and InGaAs/AlGaAs MQWs were grown using molecular beam epitaxy (MBE). High-resolution X-ray diffraction (HRXRD) and photoluminescence (PL) were employed to assess the interface smoothness and optical properties of the materials. HRXRD analysis reveals that increasing barrier growth temperature can lead to the degradation of interface quality, as well as the decrease in the indium content and well thickness in InGaAs/AlGaAs MQWs. But the PL integral signal which is the integration of the PL spectral intensity, and represents the normalized photon number produced by the PL process increase instead. The AlGaAs single layer analysis reveals increasing temperature can increase its crystal quality and interfaces smoothness, leading to enhanced radiation recombination efficiency.