Zinc oxide nanorods/polymer hybrid heterojunctions for white light emitting diodes
2011 (English)In: JOURNAL OF PHYSICS D-APPLIED PHYSICS, ISSN 0022-3727, Vol. 44, no 22, 224017- p.Article in journal (Refereed) Published
Zinc oxide (ZnO) with its deep level defect emission covering the whole visible spectrum holds promise for the development of intrinsic white lighting sources with no need of using phosphors for light conversion. ZnO nanorods (NRs) grown on flexible plastic as substrate using a low temperature approach (down to 50 degrees C) were combined with different organic semiconductors to form hybrid junction. White electroluminescence (EL) was observed from these hybrid junctions. The configuration used for the hybrid white light emitting diodes (LEDs) consists of two-layers of polymers on the flexible plastic with ZnO NRs on the top. The inorganic/organic hybrid heterojunction has been fabricated by spin coating the p-type polymer poly (3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT : PSS) for hole injection with an ionization potential of 5.1 eV and poly(9, 9-dioctylfluorene) (PFO) is used as blue emitting material with a bandgap of 3.3 eV. ZnO NRs are grown on top of the organic layers. Two other configurations were also fabricated; these are using a single MEH PPV (red-emitting polymer) instead of the PFO and the third configuration was obtained from a blend of the PFO and the MEH PPV. The white LEDs were characterized by scanning electron microscope, x-ray diffraction (XRD), current-voltage (I-V) characteristics, room temperature photoluminescence (PL) and EL. The EL spectrum reveals a broad emission band covering the range from 420 to 800 nm, and the emissions causing this white luminescence were identified.
Place, publisher, year, edition, pages
Iop Publishing Ltd , 2011. Vol. 44, no 22, 224017- p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-68688DOI: 10.1088/0022-3727/44/22/224017ISI: 000290558300018OAI: oai:DiVA.org:liu-68688DiVA: diva2:419712
Magnus Willander, Omer Nur, Siama Zaman, A Zainelabdin, Nargis Bano and I Hussain, Zinc oxide nanorods/polymer hybrid heterojunctions for white light emitting diodes, 2011, JOURNAL OF PHYSICS D-APPLIED PHYSICS, (44), 22, 224017.
Copyright: Iop Publishing Ltd