Silicon doping effects on optical properties of InAs ultrathin layer embedded in GaAs/AlGaAs:δSi high electron mobility transistors structures

► 2DEG Confinement in InAs/GaAs/AlGaAs:δSi HEMTs with different Si content. ► We have observed two-modes (L− and L+), attributed to plasmon-LO phonon coupling. ► The wavenumbers and intensities of these two modes are dependent on Si content. ► The increase of Si content results in the increase of exciton-phonon scattering.