| 초록 |
Light-emitting electrochemical cells (LECs) is an emerging concept for lighting; it involves an organic semiconductor material sandwiched between two metal electrodes. The use of cyclometalated Ir(III) complexes in lighting devices offers remarkably improved device performance compared to the use of other metal complexes. We report highly luminescent yellow and orange light-emitting electrochemical cells using cationic iridium complexes, i.e., [Ir(ppy)2(mpbi)]PF6 (Complex 1) and [Ir(bpbt)2(mpbi)]PF6 (Complex 2), which contain 2-phenylpyridine (ppy) and 2-(4-bromophenyl)benzothiazole (bpbt) as the cyclometalating ligands. The emissions of Complex 1 and Complex 2 are yellow and yellowish-green in acetonitrile solution. LECs incorporating Complexes 1 and 2 emit yellow (553 nm) and orange (600 nm) electroluminescence. Upon the meticulous selection of organic ligands, a significant increase in luminescence was achieved for Complex 1 (3636 cd/m2) over that of Complex 2 (2315 cd/m2). |
