Nitrogen-related effects on low-temperature electronic properties of two-dimensional electron gas in very dilute nitride GaNxAs1−x/AlGaAs (x = 0 and 0.08%) modulation-doped heterostructures

The low-temperature (4 K) two-dimensional (2D) electron gas mobility data versus carrier concentration in the modulation-doped dilute nitride GaAs1−xNx/Al0.3Ga0.7As (x = 0 and 0.08%) heterostructures are analyzed. Theoretical analysis is based on Fermi–Dirac statistics for the occupation of the quantum confined electronic states in the triangular quantum wells and the width of the quantum well versus 2D concentration. In addition, the mobility analysis is based on Matthiessen's rule for various scattering mechanisms. We found that the N-related neutral cluster alloy scattering together with crystal dislocations created at the interface strongly affects the electrons' mobility in the N-contained channel sample. We also found that as the electron concentration in the well increases from ∼1 × 1011 to 3.5 × 1011 cm−2 the carriers mainly occupy the first subband, tending to remain closer and closer to the hetero-interface. (paper)