Photoreflectance study of InAs ultrathin layer embedded in Si-delta-doped GaAs/AlGaAs quantum wells

► Studying HEMTs structures with different silicon doping content. ► An increase of the electric field in the InAs layer with increasing Si content. ► The interband energy transitions in the HEMTs structures have been obtained from PR. ► Experimental and theoretical values of transitions energies were in good agreement.