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Spontaneous CuPt ordering is observed in AlxIn1−xP layers grown by metal-organic vapor-phase epitaxy in pure nitrogen ambient with tertiarybutylphosphine as phosphorus precursor. Changes of the degree of ordering of the AlxIn1−xP epilayer versus annealing temperature have been investigated by using photoluminescence and transmission electron diffraction. The degree of ordering of the AlxIn1−xP layers is reduced after annealing the sample at a temperature higher than the sample growth temperature. It becomes completely disordered when the annealing temperature reaches 900°C and above.

A new two-step growth method for self-assembly growth of InAs quantum dots (QDs) with higher dot density and more size uniformity has been investigated. Using this method, InAs QDs have been grown on GaAs(001) substrates by low pressure metal–organic chemical vapour deposition technology. The samples have been characterized by atomic force microscopy and low temperature photoluminescence measurement. The dot size, dot density and the size uniformity were found to be dependent on the interruption time between the two growth steps and the growth rate of step 2 growth in the two-step growth method. Under similar growth conditions, the dot density and size uniformity of the QDs formed by using this two-step growth method have been improved by 80% and 50%, respectively, when compared to those for QDs grown by the ordinary Stranski–Krastanov growth method.

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