Solution-processed double-layered hole transport layers for highly-efficient cadmium-free quantum-dot light-emitting diodes.

The search for heavy-metal-free quantum-dot light-emitting diodes (QD-LEDs) has greatly intensified in the past few years because device performance still falls behind that of CdSe-based QD-LEDs. Apart from the effects of nanostructures of the emitting materials, the unbalanced charge injection and transport severely affects the performance of heavy-metal-free QD-LEDs. In this work, we presented solution-processed double hole transport layers (HTLs) for improving the device performance of heavy-metal-free Cu-In-Zn-S(CIZS)/ZnS-based QD-LEDs, in which N,N'-Bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine (TPD) as an interlayer was incorporated between the emitting layer and the HTL.

[Research on spectral response of CdSe quantum dots dopted polymer solar cell].

In the present paper, bulk heterojunction polymer solar cells based on P3HT:PCBM and P3HT:PCBM:QDs active layer were fabricated and measured respectively. The experimental result showed that the addition of QDs can broaden the spectral response and enhance photoinduced electron transfer. The conversion efficiency of device with QDs is about 25% higher than that without QDs.

[Effect of rubrene position on the EL performance of the device and analysis of the exciton recombination zone].

By using an ultrathin 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) layer deposited on the top of host materials, the influence of rubrene layer position on the electroluminescence (EL) spectra of organic light-emitting devices (OLEDs) was stud ied. When the rubrene layer is located at the interface between N,N'-diphenyl-N,N'-bis(1-naphthyl)-(1,18-biphenyl)-4,4'-di-amine (NPB) and tris(8-hydroxyquinoline) aluminum (AlQ) layer, EL luminescence of the device is nearly coming from rubrene emission. From the analysis of the EL spectra of the devices with different rubrene layer position, the solely contribution of rubrene and AlQ, respectively, to the luminescence of the devices is determined by spectra unmixing.

[Emitting characteristics and carrier composite regions variety of the blend of terbium complex and poly-n-vinylcarbazole].

A new rare earth complex TbGd(BA)6(bipy)2 was synthesized, which was used as an emitting material in electroluminescence. By doping with poly-N-vinylcarbazole (PVK), the stability and conductivity of terbium complex were improved. The photoluminescence of PVK, terbium complex and their blend indicated that energy transfer from PVK to terbium complex occurred.

[Effects of PBD on the electroluminescence (EL) of Tb complex doped PVK system].

Electroluminescent (EL) properties of the terbium complex [Tb(m-MBA)3 phen]2 x 2H2O doped PVK system were investigated. Two kinds of devices with the structures of ITO/PVK: Tb complex/PBD/LiF/Al and ITO/PVK: Tb complex: PBD/PBD/LiF/Al were fabricated. PBD emission appears in the EL spectra of ITO/PVK: Tb complex/PBD/LiF/Al in comparison with ITO/PVK: Tb complex: PBD/PBD/LiF/Al.

[The emission mechanisms of two kinds of Tb complexes doped in PVK system].

Two kinds of new rare earth complexes Tb(p-MBA)3phen (sample I) and Tb(p-ClBA)3 phen (sample II) were synthesized, and photoluminescence (PL) and electroluminescence (EL) characteristics of the terbium complex and PVK blended system were investigated. As to the sample I , the emission of PVK was completely restrained in the EL spectra of the blended film; while in the PL spectra, obvious emission of PVK appeared besides the emission of Tb3+. But as to the sample II, only the green emission from Tb3+ can be observed in both PL and EL spectra of the doping system.

[Electroluminescent device based on terbium complex].

Rare earth complex Tb(BA)3phen has been synthesized, which is used as an emitting material in electroluminescence. The properties of monolayer device with the rate of 1000 r x min(-1) and the impure concentration of 1:5 are the best. And the highest brightness of this device reached 26.

[Electroluminescent device based on rare earth terbium complex].

Rare earth complex TbY(m-MBA)6 (phen)2.2H20 have been synthesized, which were used as emitting materials in electroluminescence. Single-layer devices and bilayer devices with Alq as electron transmission layer have been fabricated.

[Luminescence properties of rare earth complexes Tb(BSA)4].

A new rare earth complex Tb(BSA)4 was synthesized and studied. Pure green and narrow band emission was generated from the device with structure ITO/PVK:Tb(BSA)4 /Alq3 /LiF/Al, where PVK was used to improve the film-formation and hole-transport property of the Tb(BSA)4. The absorption mechanism, and the photoluminescence and electroluminescence mechanisms are discussed.

[Photovoltaic character of organic EL devices MEH-PPV/Alq3].

An organic photovoltaic(PV) cell, ITO/MEH-PPV/Alq3/LiF/Al, was fabricated. The MEH-PPV and Alq3 are the electron-acceptor and donor in the cell, respectively. The respond region matchs the adsorption of Alq3 film.

[Emission mechanism in the Tb complex doped PVK system].

Excitation and photoluminescence (PL) spectra of the mixture terbium complex and PVK were investigated. The excitation spectrum of Tb complex dispersed PVK film is very similar to that of the pure PVK film, indicting that energy transfer occurs from PVK to Tb complex. For the overlap between the excitation spectrum of Tb complex dispersed PVK film and the PL spectrum of PVK film is very little, the ratio of occurrence for Förester energy transfer is very little.

[The luminescence characteristic of a new novel coprecipitate rare earths complexes].

A new novel coprecipitate rare earths complexes La0.6Eu0.4(BSA)3phen has been synthesized and was chosen as the emitter material in the organic electroluminescent devices: ITO/PVK: La0.