CHARACTERIZATION OF THE SHALLOW AND DEEP LEVELS IN SI DOPED GAN GROWNBY METAL-ORGANIC VAPOR-PHASE EPITAXY

Si doped GaN with room temperature free carrier concentration 1.1 x 10 (17) cm(-3) studied using the Hall effect exhibits exponential carrier freeze-out over a large range with activation energy 28.0 +/- 0.5 meV ; however, resistivity dependence on temperature suggests carrier hopp ing occurs at low temperature, GaN with greater Si concentration displ ays metallic impurity band conduction following the two-band model. De ep level transient spectroscopy results show a negligible concentratio n of other deep donors from native defects or unintentionally included impurities indicating that the active shallow donor is uniquely Si; h owever, photoluminescence tests show broad yellow emission with peak e nergy similar to 2.2 eV commonly observed in Si doped GaN.