{'fraction_non_alphanumeric': 0.02120141342756184, 'fraction_numerical': 0.016489988221436984, 'mean_word_length': 5.343283582089552, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Characterization of the Shallow and Deep Levels in Si Doped GaN Grown by Metal-Organic Vapor Phase Epitaxy

Si doped GaN with room temperature free carrier concentration 1.1× 1017 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 hopping occurs at low temperature. GaN with greater Si concentration displays metallic impurity band conduction following the two-band model. Deep level transient spectroscopy results show a negligible concentration of other deep donors from native defects or unintentionally included impurities indicating that the active shallow donor is uniquely Si; however, photoluminescence tests show broad yellow emission with peak energy ∼ 2.2 eV commonly observed in Si doped GaN.