Measurement of indium in In(x)Ga(1-x)As (x <0.02) semi-insulating crystals by photoluminescence and neutron activation analysis.

The application of the photoluminescence technique to measure indium in In(x)Ga(1-x)As semi-insulating, low dislocation density GaAs crystals for x 0.02 is investigated. This is done by measuring the band gap shift (DeltaEg) of In(x)Ga(1-x)As crystals relative to unalloyed GaAs via the energy shift of the bound exciton lines observed in the low temperature (95.5K) photoluminescence spectrum and by calibrating it with the actual ln amount determined by neutron activation analysis. Based on the results from seven crystals which included the ones grown by the liquid encapsulated Czochralski as well as by the horizontal Bridgman techniques it is found that DeltaEg (eV) is equal to 1.541 times x. The use of low temperature photoluminescence for measuring the spatial distribution of indium in the crystals is also discussed.