In 2022,Oda, Susumu; Sugitani, Takumi; Tanaka, Hiroyuki; Tabata, Keita; Kawasumi, Ryosuke; Hatakeyama, Takuji published an article in Advanced Materials (Weinheim, Germany). The title of the article was 《Development of Pure Green Thermally Activated Delayed Fluorescence Material by Cyano Substitution》.Category: iodides-buliding-blocks The author mentioned the following in the article:
Multiple resonance (MR)-effect-induced thermally activated delayed fluorescence (TADF) materials have garnered significant attention because they can achieve both high color purity and high external quantum efficiency (EQE). However, the reported green-emitting MR-TADF materials exhibit broader emission compared to those of blue-emitting ones and suffer from severe efficiency roll-off due to insufficient rate constants of reverse intersystem crossing process (kRISC). Herein, a pure green MR-TADF material (ν-DABNA-CN-Me) with high kRISC of 105 s-1 is reported. The key to success is introduction of cyano groups into a blue-emitting MR-TADF material (ν-DABNA), which causes remarkable bathochromic shift without a loss of color purity. The organic light-emitting diode employing it as an emitter exhibits green emission at 504 nm with a small full-width at half-maximum of 23 nm, corresponding to Commission Internationale d’Eclairage coordinates of (0.13, 0.65). The device achieves a high maximum EQE of 31.9% and successfully suppresses the efficiency roll-off at a high luminance. In the experiment, the researchers used 1-Chloro-3-iodobenzene(cas: 625-99-0Category: iodides-buliding-blocks)
1-Chloro-3-iodobenzene(cas: 625-99-0) belongs to organic iodides.Category: iodides-buliding-blocks The carbon-iodine bond is weaker than other carbon-halogen bonds due to the poor electronegative nature of the iodine atom. In general, organic iodides are light-sensitive and turn yellow during storage, owing to the formation of iodine.
Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com