Fabrication of Spin Valve Organic Light Emitting Devices

Lamine Fadiga

Date of Graduation

Spring 2007

Degree

Master of Natural and Applied Science in Physics

Department

Physics, Astronomy, and Materials Science

Committee Chair

Kartik Ghosh

Abstract

Device fabrication is one of the most important applicable phases in the materials science area. Spintronics and Organic Light Emitting Devices (OLED) are two of the main fields using this phase at a research level. Combining both fields results in the introduction of Spintronic-OLEDs. Their numerous advantages include non volatility, increased data processing speed and better resolution. Inorganic/organic multilayer structures such as OLEDs, spintronic devices and spin-OLEDs have been fabricated using pulsed laser deposition (for inorganic materials) and spin coating (for organic materials) techniques. The growth temperature and growth pressure of ITO, Co and ZnCoO individual layers have been optimized using X-Ray diffraction, current vs. voltage (I-V), Hall Effect and UV-VIS spectroscopy measurements. The optimum growth temperature for all three materials was determined to be the same, at 400 C, while the optimum growth pressure varied with materials. Both ZnCoO and Co were found to be ferromagnetic at room temperature. High optical transmittance of 94% was observed for the ZnCoO/ITO combination in the blue region. OLEDs, spintronic devices and ZnCoO/ITO/PFO/PEDOT/Co spin-OLEDs have been characterized via standard I-V and magneto resistance (MR) measurements. Electroluminescence was derived from the non linear I-V characteristics for the light emitting devices. A negative giant magneto-resistance effect has been observed at room temperature in the spintronic devices, while a positive MR has been observed in both the OLEDs and the spin-OLEDs.

Keywords

spintronics, Organic Light Emitting Devices, pulsed laser deposition, spin coating, giant magneto-resistance, zinc cobalt oxide

Subject Categories

Physics

Copyright

© Lamine Fadiga

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