MOCVD growth and thermal stability analysis of 1.2 µm InGaAs/GaAs multi quantum well structure

InGaAs/GaAs multiple quantum well (MQW) is desirable for many optoelectronic devices with the wavelength around 1.2 µm. However, the high defect density and instability caused by high strain have always been the problems. In this paper, an InGaAs/GaAs MQW structure was grown on GaAs substrate at low temperature by metal-organic chemical vapor deposition (MOCVD) technology. The InGaAs layers were grown with triethylgallium (TEGa) and trimethylgallium (TMGa), respectively. We studied the stability of InGaAs/GaAs MQW by evaluating the photoluminescence (PL) peak shift after annealing. It was found that the peaks of MQW grown by TEGa and TMGa were both blue-shifted after annealing. A smaller shift (<4 nm) in the MQW grown with TEGa exhibits better thermal stability compared to that of MQW grown with TMGa. This could be due to the weaker indium (In) and gallium (Ga) interdiffusion at the InGaAs/GaAs interface for the sample grown with TEGa. Furthermore, we fabricated a vertical external cavity surface emitting laser (VECSEL) based on the 6-period InGaAs/GaAs MQW grown with TEGa with an emission wavelength of ~1.2 µm.