Growth and characterization of thin Cu-phthalocyanine films on MgO(001) layer for organic light-emitting diodes

Abstract

Surface morphology and thermal stability of Cu-phthalocyanine (CuPc) films grown on an epitaxially grown MgO(001) layer were investigated by using atomic force microscope and X-ray diffractometer. The (002) textured β phase of CuPc films were prepared at room temperature beyond the epitaxial MgO/Fe/MgO(001) buffer layer by the vacuum deposition technique. The CuPc structure remained stable even after post-annealing at 350°C for 1 h under vacuum, which is an important advantage of device fabrication. In order to improve the device performance, we investigated also current-voltage-luminescence characteristics for the new top-emitting organic light-emitting diodes with different thicknesses of CuPc layer.

Evaluation of the Intramolecular Charge-Transfer Properties in Solvatochromic and Electrochromic Zinc Octa(carbazolyl)phthalocyanines

“…Phthalocyanines (Pcs) are planar macrocyclic compounds with extended 18 π-electron conjugated system that display unique electronic and optical properties. − Because of their fascinating properties as well as their thermal and chemical stability, Pcs were intensively studied as prospective compounds for photodynamic therapy (PDT) of cancer, − near-IR imaging agents, − organic-based solar cells, − and organic light-emitting diodes (OLEDs). − The aggregation behavior exhibited by the large and planar Pc macrocycles results in a drastic change of their optical properties, thus limiting their use in many applications. − For example, such undesired behavior can greatly affect the PDT activity and nonlinear optical properties by reducing the active absorbing excited-state lifetime. , Therefore, the large architectural flexibility characterized by the Pc structure can be exploited to tune the molecular properties in pursuit of optimized optical features (color, aggregation, optical absorption, etc.) for the required applications.…”

Interfacial Properties in Cu-phthalocyanine-based Hybrid Inorganic/Organic Multilayers

“…Enhancement of room-temperature (RT) magnetoresistance in a Co/Alq 3 /NiFe magnetic tunnel junction (MTJ) has been observed by inserting an Al 2 O 3 layer less than 1 nm thick between Co and Alq 3 [10]. Lately, for an Fe(001)/Cu-phthalocyanine (CuPc)/Co MTJ, the improved device functionality and reliability were reported in our earlier study by introducing a thin epitaxial MgO(001) layer at the Fe(001)/CuPc interface [11]. Here, MgO(001) acts as a spin filter [12,13] for electrons tunneling from the Fe electrode into the CuPc which is one of the π-conjugated oligomers used widely for organic thin film devices due to its high thermal and chemical stability.…”