Co-solvented solution filling and interfacial phenomena of sublimation transferred emitting layer for high-resolution OLED fabrication

We investigated co-solvented solution properties and relations in the sublimation transfer process and optimized intense pulse light (IPL) using time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis. The capillary force induced co-solvented solution into the microchannel, with the co-solvented solution properties influencing the thickness and morphology of the sublimation transferred patterns of the emitting layer. The sublimation transferred pattern was optimized by tuning the ratio of solvents that were mixtures of chlorobenzene and ortho-dichlorobenzene. In addition, an analysis of the interface between pre-deposited layers and the evaporated layer fabricated by variation of IPL energy was conducted by means of ToF-SIMS depth profiling. Host emissions or the occurrence of the intermixing of layers was detected due to insufficient or excessive IPL energy exposure. With the optimized IPL energy, the current efficiency and external quantum efficiency were maximized without a recombination zone shift or intermixing during the IPL evaporation process.