Structural phase contrast in polycrystalline organic semiconductor films observed by broadband near-field optical spectroscopy.
We demonstrate a novel near-field absorption spectrometer with 100 nm spatial resolution based on an ultrabroadband Ti:sapphire oscillator coupled to an aperture NSOM, enabling the measurement of nanoscale absorption spectra. The instrument is particularly suited for structural phase-selective imaging of organic materials at the nanoscale. We demonstrate that variations in the local absorption spectrum allow us to distinguish between the crystalline and the amorphous phases in polycrystalline phtalocyanine films, thus providing previously unavailable information on their mesoscopic texture.
Pomraenke
Robert
R
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany.
Ropers
Claus
C
Renard
Julien
J
Lienau
Christoph
C
Lüer
Larry
L
Polli
Dario
D
Cerullo
Giulio
G
D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D009930:Organic Chemicals / Q000737:chemistry*; D010316:Particle Size; D012031:Refractometry / Q000379:methods*; D012666:Semiconductors; D013057:Spectrum Analysis / Q000379:methods*; D013499:Surface Properties
D046911:Macromolecular Substances; D008567:Membranes, Artificial; D009930:Organic Chemicals