Electron Mobilities and Effective Masses in InGaAs/InAlAs HEMT Structures with High In Content

Abstract

In$_{x}$Ga$_{1-{x}}$As/In$_{y}$Al$_{1-{y}}$As HEMT structures ${\updelta }$-doped by Si were grown by molecular beam epitaxy on InP substrate. We investigated the influence of the In content on the electron mobilities and effective masses in dimensionally quantized subbands. The electron effective masses were determined by the temperature dependence of the amplitude of the Shubnikov–de Haas effect at 1.6 and 4.2 K. We found that the more the In content in quantum well (QW), the less the electron effective masses. The mobilities are higher in HEMT structures with wider and deeper QW. The energy band diagrams were calculated by using Vegard’s law for basic parameters. The calculated band diagrams are in a good agreement with the experimental data of photoluminescence spectra.