physica status solidi (a) · 1992 · 91 citations · 23 references
Natural SciencesChemistryMaterials ScienceMaterials ChemistrySemiconductor MaterialsThin FilmsGlass MaterialsOptical Properties Of SemiconductorsOptical Properties Of SolidsOrganic Electronic MaterialsOrganic SemiconductorsSemiconductor Thin FilmsInfrared Absorption SpectraInfrared Absorption SpectroscopyLight AbsorptionOptical AbsorptionOptical Thin Film CharacterizationOrganic Thin FilmsPhase-change MaterialsSemiconductor Infrared Materials
Thin films of the organic semiconductor copper phthalocyanine (CuPc) are deposited onto glass substrates maintained at room temperature, and their structures investigated using X-ray diffractometry and infrared light absorption. Films of thicknesses approximately 0.1 μm are preferentially oriented in the [001] direction. Further growth of thicker films has the effect of randomizing the orientation of the phthalocyanine crystallites, with structure mainly of the α-form. Prolonged heating at 240 °C produces a structural transformation of much of the material from the α- to the stable β-form, with the films preferentially oriented in the [201] direction. These structural changes are confirmed by infrared optical absorption analysis.
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