Search

Co/Mo multilayers with various low Co layer thickness and fixed Mo layer thickness were prepared by alternate evaporation. Transmission electron microscopy, X-ray diffraction and vibrating sample magnetometry were used to study the magnetic properties and microstructures of the films. The magnetic transition from ferromagnetic to superparamagnetic was observed at a critical thickness, accompanied with the structural evolution of the films from crystalline to amorphous. The contribution of the amorphous microstructure to the magnetic properties is discussed.

Organic light emitting devices based on tris-8-hydroxyquinoline aluminum with an ultra-thin insulating film instead of a hole-transporting layer were investigated. Three kinds of single-layer devices were fabricated with silicon dioxide (SiO 2 ), alumina (Al 2 O 3 ) or polytetrafluoroethylene (Teflon™) as the insulating films, and they showed better performance than devices without insulating films. The hole injection of these devices was also investigated using hole-only devices. The holes injection enhancement by tunneling effect and electrons blocking of the ultra-thin insulating layers were experimentally proved to have yielded high performance of single-layer devices.