We have fabricated high-efficient white organic light-emitting diodes (WOLEDs) using two types of electron transport materials with different electron mobility. The effect of the electron mobility on the device perf...
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We have fabricated high-efficient white organic light-emitting diodes (WOLEDs) using two types of electron transport materials with different electron mobility. The effect of the electron mobility on the device performance is discussed. In addition, to generate the desired white emission and high color rendering index, we perform the structure design of OLED, in which the functions of co-host of blue and green dopants on chromatic-stability are investigated. Experimental results find that the maximum color rendering index reaches as high as 91 at the voltage of 8 V.
The research of high-brightness organic light-emitting diodes, as an important branch of organic light-emitting diodes (OLEDs), makes it possible for achieving high-brightness lighting source and lasing. Heat dissip...
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The research of high-brightness organic light-emitting diodes, as an important branch of organic light-emitting diodes (OLEDs), makes it possible for achieving high-brightness lighting source and lasing. Heat dissipation and efficiency roll off, as two main factors, affect the brightness of the OLEDs heavily. In this paper, high-brightness OLEDs are obtained by utilizing pulse voltage, small areas and micro-cavity structure to minimize the effect of the two factors. The major advances, ongoing challenges and future perspectives of this research frontier are also critically discussed.
The authors have fabricated bottom gate amorphous silicon thin film transistor (a-Si TFT) array using five-step lithography process. The device shows a field effect mobility of 0.43 cm2/(V.s), on/off ratio of 7.5&...
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The authors have fabricated bottom gate amorphous silicon thin film transistor (a-Si TFT) array using five-step lithography process. The device shows a field effect mobility of 0.43 cm2/(V.s), on/off ratio of 7.5×10^6 and threshold voltage of 0.87 V. The instability of a-Si TFT is ascribed to the defect state in the a-Si channel and SiNx/a-Si interface. The present a-Si TFT array with SiNs insulator could be a significant step towards the commercialization of active matrix organic lighting diode (AM-OLED) technology.
Emission characteristics of top emitting organic light-emitting devices (TOLEDs) with Ag as reflective anode, Al/Ag as semitransparent cathode and 90 160 nm [N-(1-naphthyl)-N-phenyl-amino] biphenyl/tris-(8-hydrox...
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Emission characteristics of top emitting organic light-emitting devices (TOLEDs) with Ag as reflective anode, Al/Ag as semitransparent cathode and 90 160 nm [N-(1-naphthyl)-N-phenyl-amino] biphenyl/tris-(8-hydroxy quinoline) aluminum (NPB/Alq3) sandwiched in the electrodes are examined. The electroluminescence (EL) spectra of the TOLEDs are simulated based on the Fabry-Perot cavity theory. And the resonant modes in cavity structure of TOLEDs is discussed and clarified which can accurately describe the work principle of the devices. A fairly good match between calculated values and experimental data is achieved at different emission colors from bluish green to orange.
Seam carving is a new image retargeting method, which can alleviate the distortion on the main content of the image compared to the traditional scaling method. However, the original seam carving method uses the gradie...
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ISBN:
(纸本)9781849195058
Seam carving is a new image retargeting method, which can alleviate the distortion on the main content of the image compared to the traditional scaling method. However, the original seam carving method uses the gradient amplitudes of pixels to construct the energy map, but neglects the gradient directions of pixels. Actually, the gradient direction refers to the direction where the pixel has the maximum rate of change. We can use the gradient direction of pixels to construct the direction map, and then naturally generate multiple seams from top to bottom based on the direction map. In addition, we use the priority windows to avoid intersecting seams. Experimental results show that our method can accelerate the speed of seam carving about 98 times while maintaining the quality of the image retargeting result.
Multi-view video coding (MVC) is one of the newest video compression standards, which has better compression efficiency than single view video coding. As the coding scheme exploits spatial, temporal and inter-view dep...
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On the basis of the analysis to the framework of AM-OLED display controllers, a key module - synchronous module is studied. In this paper, a FIFO circuit (first in first out) is designed using Gray convert technology ...
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In this paper we report a novel method of transferring thermally grown vertically aligned carbon nanotubes (VA-CNTs) onto flexible substrates at room temperature with a single-step process. The transfer process is car...
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In this paper we report a novel method of transferring thermally grown vertically aligned carbon nanotubes (VA-CNTs) onto flexible substrates at room temperature with a single-step process. The transfer process is carried out by placing the CNT forests upside down on a double sided thermal release adhesive tape and peeling off the silicon substrate. Scanning electron microscope (SEM) is used to observe the transfer results. Also a second transfer using the same method but a thermal tape with higher release temperature is repeated on the as-transferred CNTs forests. The results show that this method is able to provide a novel process for transferring CNT forests at room temperature. This process will help to bring close the low cost fabrication of vertically aligned CNT structures for electronics.
Mobile devices are increasingly powerful in multimedia transmitting and browsing. However, the small screen and different aspect ratios of mobile devices lower visual quality while watching images or videos. Video ret...
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Mobile devices are increasingly powerful in multimedia transmitting and browsing. However, the small screen and different aspect ratios of mobile devices lower visual quality while watching images or videos. Video retargeting is aim at fitting an existing video into arbitrary size and aspect ratio. Previous content-aware retargeting methods are mostly high computational cost, which limits their applications on the portable devices with low computation ability. In this paper, a new crop-and-scale approach is presented to adapt video to better suit the target display. We automatically find the optimal parameters of cropping window using the dynamic programming method,, and then scale it to fit the target display. The cropping window can smoothly shift during a shot to follow the movement'of important objects. The retargeting results using our approach introduce no deformation and jitter effects over the whole video. Experimental results show the success of our approach on adapting a variety of source videos to small display sizes.
Aiming at the time redundancy in the fiat panel display (FPD) imaging process, the paper studied some problems for FPD gray scale controlling based on the fraetal theory, dissertates the construction of the space-ti...
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Aiming at the time redundancy in the fiat panel display (FPD) imaging process, the paper studied some problems for FPD gray scale controlling based on the fraetal theory, dissertates the construction of the space-time mapping topology architecture, the proposition of optimal scanning structure for FPD's gray imaging, and the creation of the fractal theoretic model. Then the logic implementation and systemapplication are presented based on the fraetal model of the optimal scan architecture, and the application results achieved target of eliminating time redundancy and increasing the scanning availability. The novel control mode that the fractal scanning IP core described with Verilog language embedded in the FPGA hardware frame can efficiently increase the imaging gray scales and quality in the FPDs scanning controller and speed up the frame frequency of displaysystem.
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