Enhanced thermoelectric properties of Ge 2 Sb 2 Te 5 thin films through the control of crystal structure

Undoped ZnO, Ga-doped ZnO, Ga and In dually doped-ZnO thin films were deposited by using magnetron Dc technique. Results from XRD, EDX and FESEM confirm influences of Ga and In dopants on the crystalline structure and the crystallinity of the ZnO thin films. Ga-doped ZnO thin films possess the highest crystallinity, while In and Ga dually doped-ZnO thin films were the worst. Through single and dual doping, the crystalline quality of the ZnO thin films can be controlled. Further researchs will be focused on the thermoelectric properties of the undoped ZnO and doped ZnO thin films.

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Transmission Electron Microscopy studies of the vacancy ordering in YSI2-X thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087124 ◽

1991 ◽

Vol 49 ◽

pp. 562-563

Author(s):

F.-R. Chen ◽

T. L. Lee ◽

L. J. Chen

Keyword(s):

Crystal Structure ◽

Electron Microscopy ◽

Thin Films ◽

Diffraction Pattern ◽

Annealing Temperature ◽

Lattice Mismatch ◽

Si Substrate ◽

Metal Thin Films ◽

Transmission Electron ◽

Vacancy Ordering

YSi2-x thin films were grown by depositing the yttrium metal thin films on (111)Si substrate followed by a rapid thermal annealing (RTA) at 450 to 1100°C. The x value of the YSi2-x films ranges from 0 to 0.3. The (0001) plane of the YSi2-x films have an ideal zero lattice mismatch relative to (111)Si surface lattice. The YSi2 has the hexagonal AlB2 crystal structure. The orientation relationship with Si was determined from the diffraction pattern shown in figure 1(a) to be and . The diffraction pattern in figure 1(a) was taken from a specimen annealed at 500°C for 15 second. As the annealing temperature was increased to 600°C, superlattice diffraction spots appear at position as seen in figure 1(b) which may be due to vacancy ordering in the YSi2-x films. The ordered vacancies in YSi2-x form a mesh in Si plane suggested by a LEED experiment.

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Ion Beam Mixing of Ni-Ti Bilayered Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118345 ◽

1985 ◽

Vol 43 ◽

pp. 290-291

Author(s):

A. K. Rai ◽

R. S. Bhattacharya ◽

M. H. Rashid

Keyword(s):

Crystal Structure ◽

Thin Films ◽

Amorphous Alloys ◽

Ion Beam ◽

Ion Bombardment ◽

High Energy ◽

Mixing Efficiency ◽

Ion Beam Mixing ◽

Enhanced Diffusion ◽

Binary Metal

Ion beam mixing has recently been found to be an effective method of producing amorphous alloys in the binary metal systems where the two original constituent metals are of different crystal structure. The mechanism of ion beam mixing are not well understood yet. Several mechanisms have been proposed to account for the observed mixing phenomena. The first mechanism is enhanced diffusion due to defects created by the incoming ions. Second is the cascade mixing mechanism for which the kinematicel collisional models exist in the literature. Third mechanism is thermal spikes. In the present work we have studied the mixing efficiency and ion beam induced amorphisation of Ni-Ti system under high energy ion bombardment and the results are compared with collisional models. We have employed plan and x-sectional veiw TEM and RBS techniques in the present work.

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