Molecular beam epitaxy growth and temperature-dependent electrical characterization of carbon-doped GaAs on GaAs(1 1 1)B

•MBE growth of carbon doped GaAs-(1 1 1)B layers on a miscut substrate.•Carbon doping concentration from 1016cm-3 to 1020cm-3•Smooth GaAs(1 1 1)B surfaces (RMS0.3nm) up to NC1020cm-3 were achieved.•p-type behavior and electrically active donor incorporation up to NC≤1019cm-3.•The carbon ionization energy in GaAs(1 1 1)B was determined to EA=26.3±0.1meV. Here we present a study of the solid source molecular beam epitaxy growth of carbon doped GaAs(1 1 1)B oriented layers in a wide doping concentration range from 1016 to 1020cm-3. The layers have been fabricated on GaAs(1 1 1)B substrates with a 1° miscut towards (2 1 1) and carbon was supplied by a heated graphite filament source. Atomic force microscopy revealed smooth surfaces (root mean square roughness 0.3 nm) up to the highest carbon concentration. The carbon concentration was determined by secondary ion mass spectroscopy. All samples exhibit p-type conductivity and temperature-dependent Hall- and resistivity measurements show carrier freeze out for doping concentration in the 1016 cm−3 and 1017 cm−3 range, whereas we observe degenerated behavior for carbon concentrations above ca. 1×1019 cm−3. The hole mobility decreases with increasing carbon concentration. The acceptor ionization energy for carbon was determined via low-temperature photoluminescence measurements to 26.3 meV. From the free hole density determined from Hall-measurements at 300 K and the overall carbon concentration, we estimate that approximately 100% of the carbon atoms are electrically active acceptors for carbon concentrations below 1×1018 cm−3. For concentrations above 1×1019 cm−3 compensation sets in and the doping efficiency is well below 100%. For comparison, samples in the standard (1 0 0)-orientation have been produced and carbon incorporation behavior during growth is very similar.