作者 Singh, Rajeev
書名 Experimental characterization of thin film thermoelectric materials and film deposition via molecular beam epitaxy
國際標準書號 9780549465355
book jacket
說明 158 p
附註 Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1226
Adviser: Ali Shakouri
Thesis (Ph.D.)--University of California, Santa Cruz, 2008
Due to the control and precision of deposition afforded by molecular beam epitaxy (MBE), it is a good choke for the deposition of thin-film thermoelectric materials in a research environment. The high resolution of source element flux rate permits materials of precise bandgap energies and carrier concentrations to be deposited. The low growth rates possible with MBE permit the deposition of materials containing high quality features at the nanometer scale. In addition, the ultra-clean environment characteristic of MBE can foster the growth of materials with exceptionally low background impurity concentrations and consequently high carrier mobilities. Although the technology of MBE can be a useful tool for epitaxial growth of thin films the science of ultra-high vacuum (UHV) can be enigmatic. Some key practical elements of UHV science will be presented and discussed to aid the MBE user in successful growth of high-quality materials. The equipment and methods used to characterize growth and material parameters as well as vacuum chamber integrity will be explored. Various calibration techniques of the growth system will be outlined. The deposition of III-V arsenide materials containing erbium arsenide nanoparticles will be briefly highlighted. Finally, thermoelectric materials and devices will be characterized using various techniques. Thermoreflectance is utilized at wavelengths in the near-infrared (NIR) regime to image the temperature distribution on the contacts of a thin-film thermoelectric module non-destructively through the module's silicon substrate
A novel thin-film thermoelectric material composed of semi-metallic ErAs nanoparticles embedded in an InGaAlAs semiconductor matrix (ErAs:InGaAlAs) is studied in this work. The MBE-grown material is designed for enhanced thermoelectric figure-of-merit (ZT) at temperatures in the range of 600 K to 900 K. Samples are designed and fabricated for accurate measurement of the thermoelectric properties of ErAs:InGaAlAs thin films
Devices designed and fabricated for direct cross-plane ZT measurement of ErAs:InGaAlAs material using the transient Harman method are characterized and analyzed at room temperature in order to determine the measurement accuracy obtained from the devices
A novel thermostat is designed and fabricated to measure thermoelectric material and device properties from room temperature to 850 K. The thermostat is capable of measuring thin-film material in-plane Seebeck coefficient and electrical conductivity as well as the cross-plane ZT of thin-film devices
State-of-the-art n-type (In0.530Ga0.376 Al0.094As)0.997ErAs0.003 thermoelectric material designed for power generation at high temperatures is characterized over a wide temperature range using the custom thermostat. (Abstract shortened by UMI.)
School code: 0036
DDC
Host Item Dissertation Abstracts International 69-02B
主題 Engineering, Electronics and Electrical
0544
Alt Author University of California, Santa Cruz