Deep blue emitting N-heterocyclic carbene platinum(II) bisalkyne complexes for light emitting applications
Organic Light Emitting Diode (OLED) devices are found in digital displays including, television screens, smartphones and computer monitors. Their efficiencies needs further improvement to significantly reduce energy consumption. This necessitates the need for highly efficient deep blue emitters critical for display and solid-state lighting. Phosphorescent metal complex based OLEDs (PhOLEDs) have the ability to harvest 100% of the generated excitons, which results in 100% internal quantum efficiency (IQE). This is possible due to the presence of the metal centre which enables efficient intersystem crossing (ISC) due to the spin orbit coupling of the heavy metal, whereby the singlet excited state (S1) is converted to the triplet excited state (T1). The radiative decay from the T1 back to the ground state S0 produces phosphorescence. The aim of this research project is to synthesise a novel class of platinum(II) deep blue emitting complexes OLED application. Several platinum(II) complexes which consist of four monodentate ligands in a trans configuration were synthesised and characterised. Detailed photophysical investigations were carried out to understand the effect of the ligands electronic properties on emission wavelengths and efficiencies. Further results from the device fabrication and evaluation are expected to provide information on electroluminescence behaviour, stability, and device efficiency.
