Exciplex electroluminescence and photoluminescence spectra of the new organic materials based on zinc complexes of sulphanylamino-substituted ligands

Abstract

We have investigated the electroluminescence spectra of the electroluminescent devices based on the new zinc complexes of amino-substituted benzothiazoles and quinolines containing the C-N-M-N chains in their chelate cycles. The spectra exhibit strong exciplex bands in the green to yellow region 540 to 590 nm due to interaction of the excited states of zinc complexes and triaryl molecules of the hole-transporting layer. For some devices, the intrinsic luminescence band of 460 nm in the blue region is also observed along with the exciplex band giving rise to an almost white color of the device emission. The exciplex band can be eliminated if the material of the hole-transporting layer is not a triarylamine derivative. We have also found the exciplex emission in the photoluminescence spectra of the films containing blends of zinc complex and triphenylamine material.

Exciplex Electroluminescence of the New Organic Materials for Light-Emitting Diodes

“…For the zinc-chelate complexes with sulphanilamino-substituted ligands, the exciplex longwave bands were observed in the PL spectra of their blends with hole-transporting materials by Kaplunov et al [44][45]. It was shown previously that the PL spectra taken from the layered structure exhibiting the exciplex EL OLEDs do not contain long-wave bands but only the intrinsic bands of components [46].…”

“…The spectra contain no intrinsic luminescence of zinc complex or PTA and exhibit only the exciplex band with maximum at 555 nm ( figure 5, curve 4). Kaplunov et al [45] studied the PL spectra of the films containing PTA, Zn(DFP-SAMQ)2 and their blends in different ratios. For the films with a relatively low fraction of PTA where PTA:Zn(DFP-SAMQ)2 = 0.5:1 and 1:1 (mass), the PL bands are close to that of Zn(DFP-SAMQ)2 with λmax = 490 nm (intrinsic emission).…”

“…Recently, spectral properties of the electroluminescent devices based on the novel zincchelate complexes of sulphanilamino-substituted quinolines and benzothiazoles were investigated and some exciplex phenomena were found [41][42][43][44][45][46]. The structures of zinc complexes are shown in Figure 1.…”

The Electroluminescence Spectra of Light-Emitting Devices Based on Zinc Complexes of Amino-Substituted Ligands

“…Recently, the emission spectra of electroluminescent devices based on the new zinc complexes of amino-substituted benzothiazoles and quinolines containing the C-N-M-N chains in their chelate cycles were investigated [1][2][3]. The electroluminescence (EL) spectra exhibit strong exciplex bands in the green to yellow region 540 to 590 nm due to the interaction of the excited states of zinc complexes and triaryl molecules of a hole-transporting layer.…”

Electroluminescence and photosensitivity spectra of organic diode structures based on zinc complexes

“…[1,2] as OLEDs are also characterisrd by photosensitivity properties. which is associated with the formation of exciplexes.…”