2026/07/27 by Jing Zhang, Zihao Zhuo, Shufang Ma +5
paper · doi:10.1088/1402-4896/ae9146
Abstract In this work, multi-period InAs/GaAs sub-monolayer quantum dot (SML-QDs) structures embedded with Al₀.₃Ga₀.₇As barrier insertion layers of 0, 1, 2, and 3 nm were prepared by molecular beam epitaxy under a fixed total barrier thickness. The morphology, strain, and optical properties of the samples were thoroughly evaluated through atomic force microscopy (AFM), high-resolution X-ray diffraction (HRXRD), and temperature-dependent photoluminescence (PL) spectroscopy. The experimental results demonstrate that the sample with a 3 nm Al₀.₃Ga₀.₇As insertion layer exhibits superior optical quality at room temperature (300 K), manifesting both the highest PL emission intensity and the narrowest full width at half maximum (16.3nm). Moreover, temperature-dependent photoluminescence (PL) spectroscopy and Arrhenius fitting analysis indicate that this sample retains a certain PL intensity at 250 K, and its carrier activation energy reaches as high as 105 meV. Therefore, incorporating the Al₀.₃Ga₀.₇As barrier insertion layer can effectively suppress the carrier thermal escape that readily occurs at high temperatures in InAs/GaAs SML-QDs, thereby improving the device emission efficiency.