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Electronically Driven Amorphization in Phase-Change In2Se3 Nanowires
journal contribution
posted on 2016-02-20, 07:55 authored by Elham Mafi, Afsoon Soudi, Yi GuWe show that the amorphization process in phase-change
In2Se3 nanowires grown by chemical vapor deposition
can be
driven by electronic effects and does not require
the conventional thermal melt-quench process. In particular, using
transmission electron microscopy, in situ single-nanowire Raman spectroscopy,
scanning Kelvin probe microscopy, and finite-element simulations,
we demonstrate that the electronic amorphization can be achieved under
optical excitations at temperatures far below the thermal melting
point. The mechanism of this electronic amorphization is likely related
to the presence of atomic bonds with different strengths in the crystalline
phase In2Se3 and the weakening of the weaker
bonds by nonequilibrium electrons. Our findings suggest that In2Se3 is a promising candidate for phase-change memory
applications, with potential advantages including energy-efficient
memory switching due to the electronic amorphization process and highly
stable data storage as a result of a high melting point compared to
Ge/Sb–Te alloys. On a more general level, these results indicate
the need to take into account the electronic effects in modeling and
understanding the phase transition processes in phase-change memories.