{'fraction_non_alphanumeric': 0.024366471734892786, 'fraction_numerical': 0.005847953216374269, 'mean_word_length': 5.149700598802395, '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}}
First-Principles Estimation of Seebeck Coefficient of Bismuth Telluride and Selenide

The first-principles electronic band structure calculation has been used to examine the relationship between the Bi/Sb composition ratio and the Seebeck coefficient in (Bi1-xSbx)2Te3. The Te/Se ratio dependence in Bi2(Te1-xSex)3 has also been investigated and the results have been compared. Because spin–orbit interaction affects the band structure to a large extent, its inclusion is crucial to a quantitative discussion on the Seebeck coefficient. We have found that the Bi/Sb or Te/Se ratio does not have a large effect on the Seebeck coefficient. However, carrier density largely influences the temperature dependence of the Seebeck coefficient. Both the p- and n-type of thermoelectric materials were examined and the results show that their stabilities have the same tendency. The carrier densities in them are largely associated with defects, which suggests that a careful defect control is very important in the production process.