Record efficiency of 1000 nm electroluminescence from a solution-processable host-free OLED. Issue 10 (23rd February 2022)

• Record Type: Journal Article
• Authors: Kovalenko, Anton; Tcelykh, Lyubov O.; Koshelev, Daniil; Vashchenko, Andrey A.; Tsymbarenko, Dmitry M.; Goloveshkin, Alexander S.; Aleksandrov, Aleksey; Burlov, Anatolii; Utochnikova, Valentina V.
• Is Part Of: Dalton transactions. Volume 51:Issue 10(2022)
• Page Start: 3833
• Page End: 3838
• Publication Date: 2022-02-23
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1dt04033b
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : An efficiency of 441 μW W −1 was obtained using a novel purposefully designed ytterbium complex as a host-free solution processable emission layer in an OLED. The value is the highest to date and was reached due to the increase of the charge mobility. Abstract : New ytterbium complexes K(Solv) x [Yb(L n )2 ] (Solv = ethanol and/or water) with 2-tosylaminobenzylidene-aryloylhydrazones (H2 L 1, aryloyl = benzoyl; H2 L 2, aryloyl = 2-naphthoyl) demonstrated high solubility and hole mobility ( ca. 2.6 × 10 −6 cm 2 V −1 s −1 ), while their electron mobility and PLQY were different. The substitution of a benzoyl substituent with naphthoyl resulted in a significant increase of the electron mobility (6.9 × 10 −7 vs. 1.7 × 10 −6 cm 2 V −1 s −1 ) and a decrease of the quantum yield (1.2% vs. 0.6%). As a result, the optimized OLEDs based on the K[Yb(L n )2 ] layer demonstrated efficiencies up to 385 μW W −1 and 441 μW W −1, indicating the superior importance of charge mobility over the quantum yield. These are the highest efficiencies of the Yb electroluminescence.