Particle-level engineering of thermal conductivity in matrix-embedded semiconductor nanocrystals.
Known manipulations of semiconductor thermal transport properties rely upon higher-order material organization. Here, using time-resolved optical signatures of phonon transport, we demonstrate a "bottom-up" means of controlling thermal outflow in matrix-embedded semiconductor nanocrystals. Growth of an electronically noninteracting ZnS shell on a CdSe core modifies thermalization times by an amount proportional to the overall particle radius. Using this approach, we obtain changes in effective thermal conductivity of up to 5× for a nearly constant energy gap.
Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Daniel C
DC
Hannah
Sandrine
S
Ithurria
Galyna
G
Krylova
Dmitri V
DV
Talapin
George C
GC
Schatz
Richard D
RD
Schaller
D019187:Cadmium Compounds / Q000737:chemistry; D004058:Diffusion; D006358:Hot Temperature; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D060739:Phonons; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry; D012666:Semiconductors; D013053:Spectrophotometry / Q000379:methods; D013440:Sulfides / Q000737:chemistry; D013696:Temperature; D013814:Thermal Conductivity; D017967:Zinc Compounds / Q000737:chemistry
D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C058667:cadmium selenide; C031238:zinc sulfide