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

The impact of growth rate on the optical and crystal quality of InGaAs/AlGaAs multi-quantum wells (MQWs) and InGaAs single layer grown by molecular beam epitaxy (MBE) is studied. Photoluminescence (PL) and high-resolution X-ray diffraction (HRXRD) are applied for evaluation of the optical, crystal quality and interfaces smoothness. The room-temperature PL integral intensity increases by 220 % when the growth rate decreases from 2 to 1 Å/s. HRXRD analysis reveals the growth rate of 1 Å/s improves crystal and interface quality of MQWs, as well as significantly enhances PL intensity. But further reduce growth rate to 0.5 Å/s, the PL integral intensity decreases, instead. At lower growth rate, more impurities can incorporate into InGaN layer and act as nonradiative recombination centers. Growth rate can effectively control crystal quality, interfaces smoothness and impurity content and thus determine the optical quality of InGaAs/AlGaAs MQWs.