No abstract

A new family of isophorone-based red fluorescent materials (A, B, C, and D) with a typical donor-π-acceptor structure was designed and synthesized for use in organic light-emitting devices (OLEDs). The asymmetrical π-conjugation structure of the isophorone skeleton facilitates the formation of highly pure products in comparison with the synthesis of pyran-containing DCM analogues. Saturated red-emitting devices with emission peaks at 640−680 nm were fabricated using these materials as dopants. The current efficiencies were moderately high and remained unchanged, even at high current density in some devices. The CIE coordinates of all the devices were comparable with or better than those of devices using DCM analogues.

A multilayer structure of copper phthalocyanine/poly(3-hexylthiophene-2,5-diyl): [6,6]-phenyl-C61-butyric acid methyl ester (CuPc/P3HT:PCBM) is used to extend the light absorption spectrum covering almost the entire visible spectrum. To maximize the light absorption, the total number of excitons created in the multilayer structure as a function of layer thickness of both CuPc and P3HT:PCBM is simulated by using the optical transfer matrix formalism. The solar cells with a device structure of ITO/PEDOT:PSS/CuPc/P3HT:PCBM/Al are fabricated with different layers thicknesses. The optimized solar cell with a high short circuit current density of 12.54mA∕cm2 and power conversion efficiency as high as 4.13% is achieved, owing to the utilization of the second optical interference peak in the multilayer structure for the enhanced light absorption.

No abstract

Articles you may be interested inInfluence of gate dielectrics on the performance of single-layered organic transistors and bi-layered organic lightemitting transistors prepared by the neutral cluster beam deposition method