An experimental investigation of the electronic transport properties of bismuth telluride nanocomposite materials is presented. The primary transport measurements are electrical conductivity, the Seebeck coefficient, and the Hall effect. An experimental apparatus for measuring the Hall effect and electrical conductivity was designed, constructed, and tested. Seebeck coefficient measurements were performed on a commercial instrument. The Hall effect and Seebeck coefficient measurements are two of the most important tools for characterizing thermoelectric materials. They are widely used in the semiconductor industry to determine carrier types, concentration, and mobility.
Further, these transport parameters are used to determine the thermal-to-electrical conversion efficiency of a thermoelectric material. The Boltzmann transport equation was used to analyze the Seebeck coefficient, carrier mobility, and electrical conductivity as a function of carrier concentration for eleven samples. The relationship between electronic transport and material/composite composition is discussed. Thermoelectric materials are materials that can convert heat to electrical energy or, the converse of this effect, use electrical current to move heat. The materials are used in various power generation and solid-state cooling devices. A good thermoelectric material requires a high Seebeck coefficient and electrical conductivity. The Seebeck coefficient and the electrical conductivity are sensitive functions of the carrier concentration n. In semiconductor materials, the electrical conductivity increases with increasing carrier concentration. Unfortunately, the Seebeck coefficient decreases with increasing carrier concentration. Much thermoelectric research aims to optimize the value by adjusting the carrier concentration. The carrier concentration is determined from a fourth measurement, the Hall effect. This thesis experimentally investigates the electronic transport in bismuth telluride, Bi2T e3, and nanocomposites formed from Bi2T e3. The primary topics of the thesis are the design, construction, and testing of a Hall effect measurement system, Hall effect measurements, and the analysis of the relationship between S, σ, and n for a series of Bi2T e3 nanocomposites. If you are looking for high quality, high purity, and cost-effective Bismuth telluride, or if you require the latest price of Bismuth telluride, please feel free to email contact mis-asia.
