{'fraction_non_alphanumeric': 0.051601423487544484, 'fraction_numerical': 0.046263345195729534, 'mean_word_length': 4.311320754716981, '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}}
High Detection Sensitivity of Ultraviolet 4H-SiC Avalanche Photodiodes

We report 4H-SiC p-i-n avalanche photodiodes (APDs) with very low dark current. When biased for a photocurrent gain M of 1000, a 100-mum-diameter device exhibits dark current of 5 pA (63 nA/cm2), corresponding to primary multiplied dark current of 5 fA (63 pA/cm2). The peak responsivity at unity gain is 93 mA/W (external quantum efficiency = 41%) at lambda = 280 nm. The excess noise factor corresponds to k = 0.1. Detection of several tens of femtowatts of ultraviolet light is reported.