{'fraction_non_alphanumeric': 0.04368029739776952, 'fraction_numerical': 0.02137546468401487, 'mean_word_length': 4.551546391752577, '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}}
Franz–Keldysh effect in 4H-SiC p–n junction diodes under high electric field along the 〈11 2 ¯ 0〉 direction

Electric-field dependence of optical absorption induced by Franz–Keldysh (FK) effect strongly depends on the value of the reduced effective mass along electric field. In this study, reverse current–voltage characteristics of 4H-SiC{11 2 ¯ 0} p–n junction diodes under sub-bandgap illumination were investigated. Under a reverse bias condition, a photocurrent induced by FK effect was observed and increased with the reverse voltage. We calculated a photocurrent with consideration of phonon-assisted optical absorption induced by FK effect in a depletion region using the reduced effective mass perpendicular to the c-axis ( μ ⊥ = 0.26 m 0 ), and the calculated values showed good agreement with the experimental values. This result indicates that the anisotropy of optical absorption induced by FK effect in 4H-SiC is small, since the reduced effective mass perpendicular to the c-axis ( μ ⊥ = 0.26 m 0 ) is close to that parallel to the c-axis ( μ ∣ ∣ = 0.28 m 0 ).