Gallium purity currently limits mobility <40×106 cm2/V s in 2DEGs grown by MBE.
Gallium purity is enhanced by high temperature outgassing in an operating MBE.
2DEG low temperature mobility in excess of 35×106 cm2/V s at density 3.0x1011/cm2.
2DEG low temperature mobility in excess of 18×106 cm2/V s at density 1.1x1011/cm2.
We describe strategies to overcome purity limitations.