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1.
A new voltage programmed pixel circuit with top emission design for active-matrix organic lightemitting diode(AMOLED) displays is presented and verified by HSPICE simulations.The proposed pixel circuit consists of five poly-Si TFTs,and can effectively compensate for the threshold voltage variation of the driving TFT.Meanwhile,the proposed pixel circuit offers an AC driving mode for the OLED by the two adjacent pulse voltage sources,which can suppress the degradation of the OLED.Moreover,a high contrast ratio can be achieved by the proposed pixel circuit since the OLED does not emit any light except for the emission period.  相似文献   

2.
This paper presents a new poly-Si pixel circuit employing AC driving mode for active matrix organic light-emitting diode (AMOLED) displays. The proposed pixel circuit, which consists of one driving thin-film tran- sistor (TFT), three switching TFTs, and one storage capacitor, can effectively compensate for the threshold voltage variation in poly-Si and the OLED degradation. As there is no light emission, except for during the emitting period, and a small number of devices used in the proposed pixel circuit, a high contrast ratio and a high pixel aperture ratio can be easily achieved. Simulation results by SMART-SPICE software show that the non-uniformity of the OLED current for the proposed pixel circuit is significantly decreased (〈 10%) with an average value of 2.63%, while that of the conventional 2T1C is 103%. Thus the brightness uniformity of AMOLED displays can be improved by using the proposed pixel circuit.  相似文献   

3.
Polycrystalline silicon(poly-Si) films were prepared by hot-wire chemical vapor deposition(HWCVD)at a low substrate temperature of 525 ℃. The influence of hydrogen on the epitaxial growth of ploy-Si films was investigated. Raman spectra show that the poly-Si films are fully crystallized at 525 ℃ with a different hydrogen dilution ratio(50%–91.7%). X-ray diffraction, grazing incidence X-ray diffraction and SEM images show that the poly-Si thin films present(100) preferred orientation on(100) c-Si substrate in the high hydrogen dilution condition.The P-type poly-Si film prepared with a hydrogen dilution ratio of 91.7% shows a hall mobility of 8.78 cm2/(V·s)with a carrier concentration of 1.3×1020 cm-3, which indicates that the epitaxial poly-Si film prepared by HWCVD has the possibility to be used in photovoltaic and TFT devices.  相似文献   

4.
在电流编程像素电路的基础上提出了一种新的交流驱动电路结构.该电路结构不仅能实现OLED的交流驱动,而且能避免由于制作过程的变化和长时间的工作引起的驱动管阈值电压漂移的现象,这种现象将导致OLED显示屏的亮度不一致.另外这种驱动方式还能消除在反偏脉冲起始和结束时刻的尖峰电流.最后,用AIM-SPICE软件对电路进行了仿真,仿真结果表明OLED器件在恢复时间内处于反偏状态.  相似文献   

5.
李大勇  刘明  Wei Wang 《半导体学报》2007,28(9):1337-1340
以有机电致发光器件(OLED)为基础的显示或照明器件,通常会受到短路故障的影响,从而使得像素失效,降低面板的亮度,进而严重地影响亮度的均匀性,并且会产生大量的功耗.本文介绍了一种新的有源OLED驱动电路,以自动检测在OLED中发生的短路故障并切换至备用OLED.该电路采用p型低温多晶硅薄膜晶体管制造.当发生短路故障时,本电路可以在不改变驱动电流的情况下,保持OLED像素的亮度维持不变.实验结果表明,本电路不仅具有容错功能,而且与标准电路相比可以显著地降低功耗.  相似文献   

6.
低温多晶硅-氧化物半导体混合集成(Lowtemperaturepolycrystallinesiliconandoxide,LTPO)的薄膜晶体管(thin-filmtransistor,TFT)背板技术融合了低温多晶硅和氧化物半导体TFT两者的优势,为低功耗、高性能显示以及功能化集成提供了新的发展机遇,获得了产业界和学术界的广泛关注。本文系统地总结和分析了LTPO相关技术与应用的研究进展以及面临的技术挑战。首先,讨论了分别针对液晶显示(Liquidcrystaldisplay,LCD)和有机发光二极管(Organiclightemittingdiode,OLED)显示的LTPO背板的集成方式,进一步总结分析了实现LTPO集成的器件结构和工艺挑战。此外,针对有源矩阵OLED显示,分析了LTPO技术用于设计兼容低帧率和高帧率驱动、具有内部补偿功能的像素电路的优势,以及在超低帧率(如1Hz)驱动情况下,TFT器件稳定性带来的影响和相关的补偿驱动方法。最后,对LTPO技术进一步发展的可能趋势进行了展望。  相似文献   

7.
为研究热退火对太阳电池用多晶硅的影响,在750~1150℃,N2和O2环境下分别对硅片进行热处理.用傅里叶红外光谱仪和准稳态光电导衰减法测量退火前后的氧碳含量和少子寿命的变化.为了比较,对有相同氧碳含量的直拉硅片进行同样处理.结果发现:在多晶和单晶片中氧碳含量下降很小,意味着没有氧沉淀产生,晶界对碳行为影响不大.多晶硅片在N2和O2环境下,850、950和1150℃下退火,少子寿命都有很大提高,并且在O2中退火比N2中退火少子寿命上升得更多,可能由于在高温退火时大量杂质扩散到晶界处,减少了复合中心.另外,间隙硅原子填充了空位或复合中心从而导致寿命提高.  相似文献   

8.
提出了一种薄膜晶体管的新结构。这种新结构充分发挥了短沟道效应和多结效应的优点。通过器件模拟,验证了此种器件结构的物理机制。通过应用这种新结构,薄膜晶体管的阈值电压、伪亚阈值斜率、开关电流比和场效应迁移率都大幅改善,并且器件的热载流子和自加热可靠性也得到了极大的改善。  相似文献   

9.
分析了4种典型的电流型AMOLED像素驱动电路的工作原理,从中总结出了补偿阈值电压漂移的方法--自动调节存储电容的电压以保证电流不变。着重提出了电流缩放比的定义,对传统结构、电流镜结构、分压结构和电容耦合结构这4种电流型AMOLED像素驱动电路的电流缩放比进行了比较和分析。在这4种电路中,电流缩放比依次增大,显示出电流型像素电路在解决电容充电时间问题上的进步与完善。

  相似文献   

10.
提出了一种新型有源矩阵有机发光显示用电流编程型像素驱动电路。该像素电路由3个开关薄膜晶体管、一个驱动薄膜晶体管、一个存储电容和两条控制线构成。仿真结果表明,该4T1C像素电路可以补偿薄膜晶体管阈值电压的非均匀性以及有机发光二极管阈值电压的漂移,发光电流的平均非均匀性为4.63%。值得指出的是,同传统的电流编程型像素电路相比,本像素电路存储电容的接法可有效提高电路响应速度。此外,还分析了寄生电容对像素电路工作的影响。  相似文献   

11.
用化学法在非晶硅表面形成Ni源,经金属诱导晶化(MIC)得到了大晶粒碟型多晶硅. 为改善以此材料作有源层的多晶硅TFT的漏电特性和均匀性,采用动态杂质吸除方法对MIC 过程所残留的Ni进行了吸除. 通过流程简化,采用6块版工艺,研制出125mm QVGA有源选址有机发光显示的多晶硅TFT选址矩阵基板.  相似文献   

12.
设计了有源OLED显示用非晶硅薄膜晶体管恒流型4-TFT像素驱动电路,并给出了驱动方法。应用HSPICE仿真了恒流型像素驱动电路的工作过程,详细分析了源(Source)电压VDD、存储电容Cs,以及开关晶体管T1、驱动晶体管T3的宽长比等参数对电路的输出特性的影响。仿真结果表明,此电路可以在整个帧周期持续供给OLED器件电流,并且解决了由于各像素驱动管阈值电压的差异带来的OLED亮度的不均匀问题。  相似文献   

13.
用化学法在非晶硅表面形成Ni源,经金属诱导晶化(MIC)得到了大晶粒碟型多晶硅.为改善以此材料作有源层的多晶硅TFT的漏电特性和均匀性,采用动态杂质吸除方法对MIC 过程所残留的Ni进行了吸除.通过流程简化,采用6块版工艺,研制出125mm QVGA有源选址有机发光显示的多晶硅TFT选址矩阵基板.  相似文献   

14.
沈匿  林祖伦  陈文彬 《电子器件》2011,34(5):550-554
为了解决驱动管阈值电压漂移带来的OLED亮度不均匀的问题,介绍了一种新的AMOLED四管像素电路,利用HSPICE仿真软件详细分析了电路各参数对其输出特性的影响,同时给出了参数设计的方法.最后从延长OLED的使用寿命出发,对电路进行了改进并根据已设计的参数进行了仿真,结果表明改进后的电路功能不变,且在驱动阶段,驱动电流...  相似文献   

15.
一种新的有源硅基OLED象素驱动电路   总被引:2,自引:0,他引:2  
王晓慧  王文博  杜寰  韩郑生   《电子器件》2007,30(5):1745-1748
提出了一种新的有源硅基有机发光二极管(OLED-on-Silicon)象素驱动电路.该电路解决了具有特定象素大小的OLED的极小象素电流(小于1μA)与传统MOS器件大的饱和驱动电流之间的不匹配问题.利用Synopsys公司的仿真软件H-spice,对该电路和传统的两管象素驱动电路进行了模拟,结果表明该电路作为OLED-on-Silicon的象素驱动更容易实现多级灰度.  相似文献   

16.
    
A new voltage-programmed driving scheme named the mixed parallel addressing scheme is presented for AMOLED displays, in which one compensation interval can be divided into the first compensation frame and the consequent N-1 post-compensation frames without periods of initialization and threshold voltage detection. The proposed driving scheme has the advantages of both high speed and low driving power due to the mixture of the pipeline technology and the threshold voltage one-time detection technology. Corresponding to the proposed driving scheme, we also propose a new voltage-programmed compensation pixel circuit, which consists of five TFTs and two capacitors(5T2C). In-Zn-O thin-film transistors(IZO TFTs) are used to build the proposed 5T2C pixel circuit. It is shown that the non-uniformity of the proposed pixel circuit is considerably reduced compared with that of the conventional 2T1C pixel circuit. The number of frames(N) preserved in the proposed driving scheme are measured and can be up to 35 with the variation of the OLED current remaining in an acceptable range. Moreover, the proposed voltage-programmed driving scheme can be more valuable for an AMOLED display with high resolution, and may also be applied to other compensation pixel circuits.  相似文献   

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