Electrical and optical properties of selectively doped Al0.25Ga0.75As/InyGa1−yAs (0.25≤y≤0.45) pseudomorphic heterostructures grown by molecular-beam epitaxy

Electrical and optical properties of highly strained selectively doped Al0.25Ga0.75As/InyGa1−yAs (0.25≤y≤0.45) pseudomorphic heterostructures grown by molecular-beam epitaxy are investigated. At a low growth temperature of 400 °C, the In mole fraction exceeds than 0.30 without degrading crystalline quality. The maximum mobility and sheet electron concentration at room temperature reach 6560 cm2/(V s) (y=0.34) and 2.94×1012 cm−2 (y=0.425), respectively. Photoluminescence measurements confirm the In mole fraction. This work suggests that InyGa1−yAs channels (y≳0.3) grown at 400 °C improve the performance of high-electron-mobility transistors.