[12a-A409-1~9] 12.4 Organic light-emitting devices and organic transistors

▼ [12a-A409-6] Stoichiometry Control for the Tuning of Passivation and Phase Distribution in Green Quasi-2D Metal Halide Perovskite Films and Light-emitting Diodes

〇(D)Tai Cheng^1,2, Satoru Watanabe^1,2, Chuanjiang Qin^1,2, Toshinori Matsushima^1,2,3, Chihaya Adachi^1,2,3 (1.OPERA, Kyushu Univ., 2.JSTA, ERATO, 3.WPI-I2CNER, Kyushu Univ.)

Keywords:Perovskite, Light-emitting Diode, Quasi-2D

Quasi-2D metal halide perovskite films are promising for efficient light-emitting diodes (LEDs), because of their efficient radiative recombination and suppressed trap-assisted quenching compared with pure 3D counterparts. However, because of the multi-order polycrystalline nature of solution-processed quasi-2D perovskite films and the grain boundary effect, the composition engineering always impacts the emitting properties with complicated mechanisms. Here, we systematically studied grain passivation and order distribution of quasi-2D perovskite films prepared with various recipes. As a result, in quasi-2D perovskite films prepared from stoichiometric recipes, the 2D components tend to function as passivators. In comparison, recipes of simply doping large organic halide salts into 3D perovskite films ensure not only the grain passivation, but also effective forming of quasi-2D phases, with avoiding unfavorable low-order phases. Quasi-2D perovskite films fabricated with a well-designed recipe achieved a high photoluminescence quantum yield of 95.3% and provided an external quantum efficiency of 14.1% for LEDs.