{'fraction_non_alphanumeric': 0.034916201117318434, 'fraction_numerical': 0.025139664804469275, 'mean_word_length': 4.925619834710743, '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}}
Photoluminescence Study of In-Situ Rare Earth Doped PVT-Grown SiC Single Crystals

Several SiC bulk crystals were grown with erbium and ytterbium as doping materials. Erbium contents determined by secondary ion mass spectroscopy (SIMS) ranged from 1.2 · 1014 cm-3 to 1.04 · 1015 cm-3, while ytterbium contents were below SIMS detection limit. Photoluminescence (PL) investigations of the characteristic 4f-4f-transition lines revealed a reduced luminescence yield in highly nitrogen and aluminum co-doped samples. Also, samples without intentional co-doping grown on the C-face showed less luminescence intensity than those grown on the Si-face. A stabilizing effect of erbium doping on the 4H polytype was observed.