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Impact of Annealing on the Thermoelectric Properties of Ge2Sb2Te5 Films

Published online by Cambridge University Press:  07 December 2012

Jaeho Lee ,
Takashi Kodama ,
Yoonjin Won ,
Mehdi Asheghi  and
Kenneth E. Goodson
Jaeho Lee
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
Takashi Kodama
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
Yoonjin Won
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
Mehdi Asheghi
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
Kenneth E. Goodson
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford, California 94305, U.S.A.
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Abstract

Thermoelectric phenomena strongly influence the behavior of chalcogenide materials in nanoelectronic devices including phase-change memory cells. This paper presents the annealing temperature and phase dependent thermoelectric properties of Ge2Sb2Te5 films including the thermoelectric power factor and the figure of merit. The Ge2Sb2Te5 films annealed at different temperatures contain varying fractions of the amorphous and crystalline phases which strongly influence the thermoelectric properties. The thermoelectric power factor increases fom 3.2 μW/mK2 to 65 μW/mK2as the crystal phase changes from face-centered cubic to hexagonal close-packed. The data are consistent with modeling based on effective medium theory and suggest that careful consideration of phase purity is needed to improve the figures of merit for phase change memories and potentially for thermoelectric energy conversion applications.

Keywords

thermoelectricthin filmphase transformation
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1490: Symposium B – Thermoelectric Materials Research and Device Development for Power Conversion and Refrigeration , 2013 , pp. 223 - 228
Copyright
Copyright © Materials Research Society 2012 

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References

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