•New organic compounds (BTDs) was synthesized as semiconductor materials.•ODPA was used as SAMs to modify the dielectric substrate.•SAMs improve the performance and reliability of BTDs based device.Three kind of 1,2,4,5-benzenetetracarboxylic diimides (BTDs) with halogenated phenyl groups were synthesized through one-step reaction with high yields. Top-contact organic field-effect transistors (OFETs) were fabricated via vacuum deposition of BTDs as the semiconducting channel materials on N-octadecylphosphonic acid (ODPA) treated SiO2/Si substrates. The electronic characterization was measured in ambient condition. All these derivatives exhibit excellent n-channel OFET transport with the highest mobility up to 9.2 × 10−2 cm2v−1s−1 for BTD-ClAN deposited at room temperature. The crystallinity and morphology of film were improved by modified the substrate and demonstrated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Our results indicates that introducing electron-withdrawing substituents into 1,2,4,5-benzenetetracarboxylic diimides is an effective way to achieve high OFETs performance.Download high-res image (115KB)Download full-size image

•Near infrared emission from a Dy (III) complex.•Radiative decay time of the 4F9/2 excited state of this complex.•Nature life-time of the Dy complex obtained by Judd–Ofelt theory analysis.We have synthesized a trivalent dysprosium ion (Dy3+) complex Dy(PM)3(TP)2 [where PM=1-phenyl-3-methyl-4-isobutyryl-5-pyrazolone and TP=triphenyl phosphine oxide]. Besides visible emission peaked at 480, 572 and 655 nm, near-infrared emission with sharp emission bands range from 800 nm to 1700 nm were detected from this complex. The Judd–Ofelt theory was introduced to calculate the radiative transition rate and the radiative decay time for the 4F9/2→6LJ′ transitions of Dy3+ ion in this complex. The calculated radiative lifetime of the 4F9/2 excited state was 410 μs, compared with the measured luminescent lifetime 17.6 μs, we obtained the radiative quantum efficiency of the 4F9/2 excited state of 4.3% from this Dy (III) complex.

We investigated near-infrared electroluminescence properties of two lanthanide complexes Yb(PMBP)3Bath [PMBP = tris(1-phenyl-3-methyl-4-(4-tert-butylbenzacyl)-5-pyrazolone); Bath = bathophenanthroline] and Yb(PMIP)3TP2 [PMIP = tris(1-phenyl-3-methyl-4-isobutyryl-5-pyrazolone); TP = triphenyl phosphine oxide] by fabricated the double-emission-layers devices. From the device characteristics, it is known that holes are easier to transport in Yb(PMIP)3TP2 layer and electrons are easier to transport in Yb(PMBP)3Bath layer, at the same time, both of the two complexes can be acted as emission layers in the device. The recombination region of carriers has been confined in the interface of Yb(PMIP)3TP2/Yb(PMBP)3Bath, and pure Yb3 + ion characteristic emission centered at 980 nm has been obtained. The device shows the maximum near-infrared irradiance as 14.7 mW/m2 at the applied voltage of 17.8 V.Highlights► Near-infrared electroluminescent devices with Yb(III) complexes as emission layers. ► Double-emission layer device structure introduced to balance carriers. ► Improved performance of double-emission layer device.