Improving the luminescent and electronic properties of OLED materials through structural modification

Organic light emitting diodes (OLEDs) technology has attracted increasing research efforts from both industry and academia in the past decade. One of the main advantages of using organic materials in light emitting devices is the tuneability of the materials. A good knowledge of the structure-property relationship in these materials is indispensable in order to take advantage of the tuneability. In this work, we will report our investigation of the luminescent and electronic properties of structurally modified oligo(phenylenevinylene)s (OPVs), and oligo(paraphenylene)s (OPPs). We are particularly interested in understanding the relationship of the electroluminescent (EL) and charge transport properties with the molecular structures and related thin film morphology. EL properties were characterized on multilayer organic light emitting devices fabricated using vacuum deposition, the charge transport properties were characterized by current-voltage and transient electroluminescent measurements. The molecular structure modification leads to significant change in emission colors, HOMO-LUMO levels, charge carrier mobilities, and device stability.