Quantitative analysis of carbon concentration in MOMBE p-GaAs by low-temperature photoluminescence

Abstract
Several features of low‐temperature (2‐K) photoluminescence (PL) spectra are used for a quantitative determination of the carbon concentration below 1018 cm3 in GaAs samples grown by metalorganic molecular‐beam epitaxy. We present a close correlation between specific PL features and hole concentration together with a calibration of the carbon content with respect to the hole concentration. This calibration was done directly on samples implanted with a known amount of carbon (1×1016 cm3) and via local vibrational mode and secondary ion mass spectrometry analysis of samples doped to around 1018 cm3. The method permits a fast and nondestructive determination of the carbon content from PL measurements.