Crystalline/amorphous Raman markers of hole-transport material NPD in organic light-emitting diodes

Takuro Sugiyama, Yukio Furukawa, Hidetoshi Fujimura

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    18 Citations (Scopus)


    Raman marker bands characteristic of solid-state structure have been found for N,N′-di-1-naphthaleyl-N,N′-diphenyl-1,1′-biphenyl-4, 4′-diamine (NPD), which is used as a hole-transport material in organic light-emitting diodes. The widths of the marker bands observed for an amorphous state at 1607, 1290, and 1192 cm-1 are broader than those for the crystalline state observed at 1609, 1288, and 1198 cm-1. These Raman bands are found to be useful for detecting the crystallization, which may cause degradation of organic light emitting diodes, of amorphous NPD films.

    Original languageEnglish
    Pages (from-to)330-333
    Number of pages4
    JournalChemical Physics Letters
    Issue number4-6
    Publication statusPublished - 2005 Apr 12


    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Spectroscopy
    • Atomic and Molecular Physics, and Optics
    • Surfaces and Interfaces
    • Condensed Matter Physics

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