Title :
Structural and thermoelectric properties of MBE-grown doped and undoped BiSb alloy thin films
Author :
Cho, Sunglae ; DiVenere, Antonio ; Kim, Yunki ; Wong, George K. ; Ketterson, John B. ; Meyer, Jerry R. ; Hoffman, Craig A.
Author_Institution :
Dept. of Phys. & Astron., Northwestern Univ., Evanston, IL, USA
Abstract :
We have successfully grown BiSb alloy thin films on CdTe(111)B over a wide range of Sb compositions using molecular beam epitaxy. It is well known that small bandgap (~18 meV) bulk BiSb alloys are good n-type thermoelements at liquid nitrogen temperature. We have observed that the power factor (S2σ) for MBE-grown 1 μm thick BiSb thin films grown on CdTe(111) peak at a significantly higher temperature (250 K) than previous results for the bulk alloy (80 K), possibly due to an enhanced bandgap. For doping experiments we used the group IV(VI) element Sn(Te) as an acceptor(donor). Thermoelectric Power (TEP) and electrical resistivity were studied in the range of temperatures 2-300 K. Doping Sn into the BiSb system causes the TEP to change sign (from negative to positive), and the maximum value of the TEP can be controlled with the Sn dopant concentration
Keywords :
X-ray diffraction; bismuth compounds; electrical resistivity; energy gap; molecular beam epitaxial growth; reflection high energy electron diffraction; semiconductor doping; semiconductor epitaxial layers; semiconductor growth; thermoelectric power; 1 mum; 18 meV; 2 to 300 K; BiSb; BiSb films; MBE; electrical resistivity; enhanced bandgap; molecular beam epitaxy; n-type thermoelements; power factor; thermoelectric properties; Doping; Electric resistance; Molecular beam epitaxial growth; Nitrogen; Photonic band gap; Reactive power; Temperature; Thermoelectricity; Tin alloys; Transistors;
Conference_Titel :
Thermoelectrics, 1998. Proceedings ICT 98. XVII International Conference on
Conference_Location :
Nagoya
Print_ISBN :
0-7803-4907-5
DOI :
10.1109/ICT.1998.740374
