Growth and Brilliant Photo-Emission of Crystalline Hexagonal Column of Alq3 Microwires

• Main Authors: Seokho Kim, Do Hyoung Kim, Jinho Choi, Hojin Lee, Sun-Young Kim, Jung Woon Park, Dong Hyuk Park
• Format: Article
• Language: English
• Published: MDPI AG 2018-03-01
• Series: Materials
• Subjects: organometal; Alq3; photoluminescence; crystallinity; surfactant; confocal microscope
• Online Access: http://www.mdpi.com/1996-1944/11/4/472

We report the growth and nanoscale luminescence characteristics of 8-hydroxyquinolinato aluminum (Alq3) with a crystalline hexagonal column morphology. Pristine Alq3 nanoparticles (NPs) were prepared using a conventional reprecipitation method. Crystal hexagonal columns of Alq3 were grown by using a surfactant-assisted self-assembly technique as an adjunct to the aforementioned reprecipitation method. The formation and structural properties of the crystalline and non-crystalline Alq3 NPs were analyzed with scanning electron microscopy and X-ray diffraction. The nanoscale photoluminescence (PL) characteristics and the luminescence color of the Alq3 single NPs and their crystal microwires (MWs) were evaluated from color charge-coupled device images acquired using a high-resolution laser confocal microscope. In comparison with the Alq3 NPs, the crystalline MWs exhibited a very bright and sharp emission. This enhanced and sharp emission from the crystalline Alq3 single MWs originated from effective π-π stacking of the Alq3 molecules due to strong interactions in the crystalline structure.