Optical spectroscopy of GaN grown by metalorganic vapor phase epitaxy using indium surfactant

The effect of In surfactant during metalorganic vapor phase epitaxial growt h on sapphire substructure on the properties of GaN layers is studied using time-resolved photoluminescence. cathodoluminescence. and scanning electro n microscopy. The samples are divided into two groups. where hydrogen and n itrogen, respectively, have been used as a carrier gas during growth. It is shown that In-doped samples have a lower dislocation density, a narrower p hotoluminescence linewidth, and a longer foe exciton lifetime. The influenc e of indium is stronger for GaN layers grown in nitrogen-rich conditions. T he improvements of structural and optical properties are attributed to the effect of In on dislocations. (C) 2000 American Institute of Physics. [S000 3-6951(00)02723-6].