The structural and optical properties of multiquantum‐well (MQW) structures grown by molecular beam epitaxy are strongly dependent on the substrate temperatureTsduring the growth. A study of the optimization of MQW structures as a function ofTsis carried out using optical and electron microscopy and photoluminescence characterization. Optimal temperatures in the range 670–730 °C are shown to yield smooth free surfaces and interfaces and high quantum efficiencies.