Modulation‐doped Ga0.47In0.53As/Al0.48In0.52As single period heterostructures were prepared by molecular beam epitaxy. Current versus electrical field characteristics were investigated in a lattice temperature range of 10–300 K. Measurements were performed at electric field strengths as high as 2 kV/cm which is comparable to the field strengths attained in normally‐off field effect transistors. Mobilities as high as 8960 cm2/Vs at 300 K, 61 100 cm2/Vs at 75 K, and 93 000 cm2/Vs at 10 K were measured and were found to be proportional to temperature approximately as &mgr;∝T−1.74. Mobility enhancement was observed in the single period Ga0.47In0.53As/Al0.48In0.52As system irrespective of the relative position of the larger band gap Si‐doped Al0.48In0.52As.