Effects of thermal preparation on Copper Phthalocyanine organic light emitting diodes

We studied the effects of interface morphology and phase transition on the performance of Copper Phthalocyanine (CuPc) organic light emitting diodes (OLEDs) due to thermal preparation of CuPc. CuPc thin films were used as hole injection layers for these OLEDs. The most common polymorphs are the metastable α-phase and the stable β-phase for CuPc films. The current-voltage-luminance performance of OLEDs is affected by different grain organization in the CuPc layer. We examined the changes in the phase state, the surface morphology and roughness by using a UV-vis spectroscope, a scanning electron microscope, and an atomic force microscope.