title: Solid-phase flexibility in Ag2Se semiconductor nanocrystals.
abstract: Nanocrystals are known to alter the relative stability of bulk solid phases. Here we test the limits of this effect on Ag2Se nanocrystals, a promising new electronic and infrared material. In the bulk, Ag2Se exhibits a solid-solid phase transition to a superionic conducting phase at moderate temperatures. We map this phase transition as a function of size, temperature, and surface treatment in Ag2Se core-only and core-shell nanocrystals. We show that the transition can be tuned not just below but also above the bulk phase-transition temperature. This phase flexibility has implications for applications in optoelectronic and phase-memory devices.
authors.affiliation: Optical Materials Engineering Laboratory, ETH Zurich , 8092 Zurich, Switzerland.
authors.forename: Ayaskanta
authors.initials: A
authors.lastname: Sahu
authors.forename: Daniele
authors.initials: D
authors.lastname: Braga
authors.forename: Oliver
authors.initials: O
authors.lastname: Waser
authors.forename: Moon Sung
authors.initials: MS
authors.lastname: Kang
authors.forename: Donna
authors.initials: D
authors.lastname: Deng
authors.forename: David J
authors.initials: DJ
authors.lastname: Norris