Enhanced energy transfer between poly-(vinylcarbazole) and tris(2-phenylpyridine) iridium(III) via the switch of molecular conformation induced by different solvents and UV light irradiation

In this letter, we reported the influence of solvents or UV light irradiation on EL efficiency of phosphorescence-doped PLEDs. The molecular conformation of host material PVK depended on different treatment process, which can be switched from side-by-side structure to face-to-face structure. More triplets are formed inside PVK molecular with face-to-face conformation structure that induced lower carrier transport ability. Therefore, it is significant to optimize the treatment process of phosphorescence-doped PLED to achieve higher efficiency by molecular conformation controlling.