Near-infrared electroluminescence from double-emission-layers devices based on Ytterbium (III) complexes

We investigated near-infrared electroluminescence properties of two lanthanide complexes Yb(PMBP)(3)Bath [PMBP = tris(1-phenyl-3-methyl-4-(4-tert-butylbenzacyl)-5-pyrazolone); Bath = bathophenanthroline] and Yb(PMIP)(3)TP2 [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)(3)TP2 layer and electrons are easier to transport in Yb(PMBP)(3)Bath 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)(3)TP2/Yb(PMBP)(3)Bath, 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/m(2) at the applied voltage of 17.8 V. (c) 2011 Elsevier B.V. All rights reserved.