Direct detection of hole gas in Ge-Si core-shell nanowires by enhanced Raman scattering.
We report the direct detection of hole accumulation in the core of Ge-Si core-shell nanowire heterostructures by a Fano resonance between free holes and the F2g mode in Raman spectra. Raman enhancements of 10-10 000 with respect to bulk were observed and explained using finite difference time domain simulations of the electric fields concentrated in the nanowire. Numerical modeling of the radial carrier concentration revealed that the asymmetric line-shape is strongly influenced by inhomogeneous broadening.
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States.
Shixiong
S
Zhang
Francisco J
FJ
Lopez
Jerome K
JK
Hyun
Lincoln J
LJ
Lauhon
D003198:Computer Simulation; D005740:Gases / Q000737:chemistry*; D005857:Germanium / Q000737:chemistry*; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D016062:Porosity; D012542:Scattering, Radiation; D012825:Silicon / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
D005740:Gases; D046911:Macromolecular Substances; D053769:Nanocapsules; D005857:Germanium; D012825:Silicon