Paper Title
THERMOELECTRIC BEHAVIOR OF BI2TE2.55SE0.45 WITH A TUNABLE SEEBECK COEFFICIENT: A COMPARISON BETWEEN COARSE NEEDLE-LIKE STRUCTURE AND BULK NANOSTRUCTURED ALLOYS

Abstract
Abstract - In this study, we compare the thermoelectric properties of coarse-grained n-type Bi2Te2.55Se0.45alloy prepared by induction melting with the bulk-nanostructured prepared by ball milling and hot-pressing techniques. The corresponding thermoelectric properties showed different behavior for each material processed using different routes. The most striking result of the study is observing a p-type behavior and charge carrier transition from p- to n-type for the coarse-grained alloy. These observed phenomena are related mainly to the unique needle-like microstructure accompanied by high lattice strain. Lastly, the obtained figure-of-merit values for the coarse needle-like structure and bulk nanostructured Bi2Te2.55Se0.45alloys are 0.20 and 0.80 at their optimum temperatures of 60 and 120 °C, respectively. Keywords: Thermoelectric; Seebeck coefficient; mechanical milling; induction melting; bismuth telluride.