Summary: | 碩士 === 國立中央大學 === 電機工程學系 === 107 === Due to the demand of energy and the concern on pollution, renewable energy has attracted much attention in recent years. Among them, thermoelectric energy can be achieved by waste heat recovery from direct conversion from thermal energy to electricity. The conversion efficiency of thermoelectric materials is mainly determined by its thermoelectric figure of merit (ZT). The improvement of the ZT is keen for current research.
In this thesis, The ZTs of medium- and low-temperatured P-type thermoelectric material BiCuSeO and MgAgSb were studied, respectively. Different from conventional hot pressing or spark plasma sintering process, we used ball-milling technique to obtain nanometer-sized powders, and then cold-pressed the powders and annealed at different temperatures and time to study P-type MgAgSb and Bi0.92Ag0.08CuSeO bulks. High Seebeck coefficient of 448.86 (μV/K) and a minimum thermal conductivity of 0.272 (W/m-K) were achieved. Eventually, a thermoelectric module was fabricated using P-type Bi0.92Ag0.08CuSeO and N-type Mg2Si0.4Sn0.6, and the maximum output power reached 43.1 (μW) at a temperature difference of 46 degrees.
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