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In this study, a white light organic light-emitting diode is fabricated by solution processes. The focus of the research is to extend the lifetime of device. A hole transport layer doped with P-type material (F4-TCNQ) and a stepped electron transport layer TPBi (blocking holes and lowering the LUMO energy level) were employed in the device structure. And each layer thickness was optimized. At 9 V, the brightness can reach 206 cd/m2, current efficiency 1.29 cd/A, and the device lifetime is extended from 0.8 to 8 hours. The CIE color-coordinates of white OLED samples are (0.38, 0.28).

Most small molecule organic light emitting diode (SM-OLED) device structures are made in one layer using solution-based processing because the solution is usually a high dissolvent material that easily attacks the layer below it. We demonstrate a simple and reliable stamping technique for fabricating multi-solution process flexible white SM-OLEDs. The structure is anode/spin-hole injection layer/spin-emitting layer/stamping-electron transport layer/cathode. Poly(di-methyl silane) (PDMS) stamp is used for transferring electron transport layer. An intermediate ultraviolet-ozone surface treatment is introduced to temporarily modify the PDMS stamp surface. Then, the solution-based electron transport layer film can therefore be uniformly formed on top of the PDMS surface. After that the electron transport layer film on the PDMS stamp is transfer-printed onto the emitting layer with suitable heating and pressing. A solution-based processing is successfully established to efficiently fabricate flexible white SM-OLEDs. The SM-OLEDs were obtained at the current density of 20 mA/cm 2 , luminance of 1062 cd/m 2 , current efficiency of 5.57 cd/A, and Commission internationale de l'eclairage coordinate of (0.32, 0.35).

In this paper, the flexible white organic light-emitting diodes (WOLED) was fabricated on polyethylene naphthalate (PEN) with structure of ITO/EHI608 (75 nm)/HTG-1 (10 nm)/3% EB502:0.8% EY53 (5 nm)/3% EB502 (35 nm)/Alq3 (10 nm)/LiF (0.8 nm)/Al (150 nm) and was compared with glass substrate the same structure. It was seen that the performances of flexible and glass substrate are almost the same. The luminance, current efficiency, and CIE coordinates of flexible device is 6351 cd/m2, 12.7 cd/A, and (0.31, 0.38) at 50 mA/cm2, respectively. Then, an Al2O3/HfO2 film on polyethylene terephthalate (PET) was deposited using atomic layer deposition (ALD) as a thin film encapsulation layer have been described and compared, such as the characteristics of water permeability and lifetime of flexible WOLED. The results show that the PET/ALD film low value of about 0.04 g/m2d, and the PET film shows WVTR of about 3.8 g/m2/d. The lifetimes of PET/ALD and PET encapsulations are 840 min and 140 min, respectively. Simultaneous deposition of ALD film on PET film gave the lifetime of flexible WOLED is six times longer than device without ALD encapsulation.

Display Omitted Investigating PhOLEDs with different solvents and dopants concentrations.High efficiency white PhOLEDs induced by the electron transport/hole blocking material.To achieve efficient and low-cost small-molecule-based white PhOLEDs. In this study, white phosphorescent organic light-emitting diodes (PhOLEDs) have been demonstrated with small molecule by using solution processes. Spin-coating is employed as the way for deposition method. 4,4'-N,N'-dicarbazole-biphenyl (CBP) which is typical small molecule based ink is used for spin-coating method, and three phosphorescent dopants materials, Firidium(III) bis(4,6-difluoro phenyl)-pyridinato-N,C2'] picolinate (FIrpic), bis1-(phenyl) isoquinoline) iridium(III) acetyl acetonate (Ir(piq)2 (acac))], and iridium(III) tris(2-phenylpy-ridine) (Ir(ppy)3) were prepared. For spin-coating processes, various parameters properties were investigated including materials concentrations, solvents effect, and electron transporting materials to get high efficiency and white color of white PhOLED device. As a result, the precisely controlled solution processes could be a promising technology for solution process can be a good alternative of vacuum deposition technology.

A hybrid approach integrating a Taguchi orthogonal table with an irregular design of experiments (DOE) method was proposed for selecting an optimal material structure of blue organic light emitting diodes in order to achieve multi-objective quality characteristics of devices. Analysis of variance (ANOVA) was adopted to identify significant factors before regression models were obtained. Finally, an optimal material structure was determined by maximizing a desirability function relating to selected critical quality characteristics including the driving voltage, the luminance, and luminance efficiency.

A blue small-molecular organic light-emitting diode (SM-OLEDs) based on a solution-process is investigated in this study. Design of experiment (DOE) with response surface methodology (RSM) was applied to optimize the driving voltage and current efficiency of blue SM-OLED devices. The spin-coating speed of the PEDOT: PSS as hole injection layer and the 26DCzPPy: FIrpic as emitting layer were chosen as two main process input factors. Analysis of variance (ANOVA) was adopted to identify significant factors before regression models were obtained. The optimal material structure was determined by minimizing and maximizing a desirability function relating to selected critical quality characteristics including the driving voltage and current efficiency, respectively.