Pyridine-Incorporated Dihexylquaterthiophene: A Novel Blue Emitter for Organic Light Emitting Diodes (OLEDs)

Abstract

The synthesis and characterisation of 2,5-bis(5′-hexyl-[2,2′-bithiophen]-5-yl)pyridine (Th4PY) and its use as a blue emitter in organic light emitting diodes (OLEDs) is reported. Th4PY was synthesised in high yield using a straightforward Suzuki coupling route with commercially available starting materials. As Th4PY is both soluble and has low molecular weight, blue OLEDs were fabricated using both spin-coating and vacuum deposition thin film processing techniques to study the effect of processing on device performance. OLED devices using a spin-coated layer consisting of 4′,4′′-tris(N-carbazolyl)triphenylamine (TCTA) and 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) as a host matrix together with Th4PY as emitter exhibited highly efficient sky-blue emission with a low turn-on voltage of 3 V, a maximum brightness close to 15000 cd m–2 at 8 V, and a maximum luminous efficiency of 7.4 cd A–1 (6.3 lm W–1) with CIE coordinates of x = 0.212, y = 0.320. The device performance characteristics are compared using various matrices and processing techniques. The promising sky-blue OLED performance, solution processability, and ambient stability make Th4PY a promising blue emitter for application in OLEDs.

Dithienylbenzothiadiazole-Based Donor-Acceptor Organic Semiconductors and Effect of End Capping Groups on Organic Field Effect Transistor Performance

“…27 Our group has been also working on such class of D-A-D based materials since last few years and trying to understand the structure-property relationship of these materials through fine tuning in the structural design and its effect on various optoelectronic properties (absorption, emission, energy level tuning, morphology and charge transport behavior). [30][31][32] These materials have been successfully used in as active layers in OFET and organic photovoltaics (OPV) devices. In this work, we are reporting design and [1,2,5]thiadiazole (TFP-TBT).…”

The 2nd Molecular Materials Meeting (M3@Singapore)

“…Among the original papers are contributions by Liu et al [14] (Institute of Chemistry, Chinese Academy of Sciences, China), who examined the structure-property relationships for phenyl-1H-pyrrole endcapped thiophene semiconductors that are generally used as active layers of organic field-effect transistors; these compounds exhibit clear p-type semiconducting behaviour. Sonar et al [15] (IMRE, Singapore) report a pyridine-incorporated dihexylquaterthiophene (Fig. 4a) with promising emission properties that can be potentially used as blue emitters in organic light-emitting diode applications.…”

“…[12] Th4-PY Porential blue emitter (a) Pyridine-incorporated dihexylquaterthiophene as a promising blue emitter for organic light-emitting diode applications. [15] (b) Twodimensional photopattern generated by photo-oxidation of a carbazole-containing 1-phenyl-1-alkyne film in air at room temperature for 5 min (photo taken under UV illumination). [16] 2nd M3@Singapore…”

The 3rd Molecular Materials Meeting (M3) @ Singapore

“…heterocyclic dyes for efficient dye-sensitised solar cells, [12] phenyl-1H-pyrrole end-capped thiophenes for organic field-effect transistors, [13] and pyridine incorporated dihexylquaterthiophene as blue emitter in organic light emitting diode applications. [14] In this commemorative edition, seven papers are selected as highlights of the meeting. Bai et al [15] (Institute of Materials Research and Engineering, Singapore) introduced a new dinuclear Cu(II) complex ( Fig.…”