Selenium doped high-index GaAs epilayers grown by molecular beam epitaxy

Using elementary Se we grew Se-doped GaAs films on GaAs (111), (411), (711) and (100) substrates by molecular beam epitaxy. The films grown on all the high-index substrates showed n-type conduction and the maximum carrier concentration reached 2.1 × 10¹⁹ cm^?3 for the film grown on the (411)B substrate. The carrier concentration began to saturate at a Se concentration near 10¹⁹ cm^?3 but continued to increase up to a Se concentration of 2 × 10²⁰ cm^?3. Above 2 × 10²⁰ cm^?3 Se concentration, slow reduction of the carrier concentration was observed. We obtained excellent surface morphology when n-type GaAs films were grown on (411)A and (711)B substrates even at a Se concentration of 7 × 10²⁰ cm^?3.