Design of a photonic crystal microcavity for biosensing

We have designed an air-bridged PhC microcavity with high sensitivity and a high quality factor.The structure parameters of the microcavity are optimized by three-dimensional finite-difference time-domain method. We compare the performance of a silicon-on-insulator PhC microcavity and an air-bridged PhC microcavity,and analyze the effect of the thickness of the slab and the radius of the defect hole on the performance of the air-bridged PhC microcavity.For a thinner slab and a larger defect hole,the sensitivity is higher while the quality factor is lower.For the air-bridged photonic crystal slab,the sensitivity can reach 320-nm/RIU(refractive index unit) while the quality factor keeps a relatively high value of 120 by selecting the proper slab thickness and the defect hole radius,respectively,when the refractive index is 1.33.This is meaningful for low-detection-limit biosensing.     

应用于生物传感的光子晶体微腔设计

We have designed an air-bridged PhC microcavity with high sensitivity and a high quality factor.The structure parameters of the microcavity are optimized by three-dimensional finite-difference time-domain method. We compare the performance of a silicon-on-insulator PhC microcavity and an air-bridged PhC microcavity,and analyze the effect of the thickness of the slab and the radius of the defect hole on the performance of the air-bridged PhC microcavity.For a thinner slab and a larger defect hole,the sens...     

Lasing Behavior of BMPPV:PVK Mixture in Microcavity

The surface emitting microcavity is formed by sandwiching a polymer film containing poly (para-phenylene vinylene) (BMPPV) and poly (N-vinylcarbazole)(PVK) between a DBR with a reflectivity of 99.5% and a silver film.The sample is optically pumped by a 337.1 nm line of nitrogen laser with 10 ns pulses at 20 Hz repetition rate.The lasing phenomenon is observed in BMPPV and PVK mixture microcavity .The full width at half maximum( FWHM) is 6 nm at the peak wavelength of 460 nm.The lasing threshold energy is estimated to be about 5μJ.     

一种基于低温多晶硅薄膜晶体管的交流AMOLED像素补偿电路

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.     

Investigation of top-emitting OLEDs using molybdenum oxide as anode buffer layer

A high-effective bottom anode is essential for high-performance top-emitting organic light-emitting devices (OLEDs). In this paper, Ag-based top-emitting OLEDs are investigated. Ag has the highest reflectivity for visible light among all metals, yet its hole-injection properties are not ideal for anodes of top-emitting OLED. The performance of the devices is significantly improved using the molybdenum oxide as anode buffer layer at the surface of Ag. By introducing the molybdenum oxide, the hole injection from Ag anodes into top-emitting OLED is largely enhanced with rather high reflectivity retained.     

ITO作为电流扩展层的AlGaInP 发光二极管可靠性研究

Three aging experiments were performed for AlGaInP light emitting diodes（LED） with or without indium tin oxide（ITO）,which is used as a current spreading layer.It was found that the voltage of the LED with an ITO film increased at a high current stressing,while there was little change for that of the LED without the ITO.The results of the LEDs with different thicknesses of the ITO film show that the LED with a thicker ITO has a higher reliability.The main reason for the voltage increase of the LED with the ITO film might be the current crowding in the ITO film around the P-type electrode.     

Electrochemical investigation of copper chemical mechanical planarization in alkaline slurry without an inhibitor

This work investigates the static corrosion and removal rates of copper as functions of H202 and FA/OIIconcentration, and uses DC electrochemical measurements such as open circuit potential （OCP）, Tafel ana- lysis, as well as cyclic voltammetry （CV） to study HaOa and FA/OIIdependent surface reactions of Cu coupon electrode in alkaline slurry without an inhibitor. An atomic force microscopy （AFM） technique is also used to measure the surface roughness and surface morphology of copper in static corrosion and polishing conditions. It is shown that 0.5 vol.% H202 should be the primary choice to achieve high material removal rate. The electro- chemical results reveal that the addition of FA/O II can dissolve partial oxide film to accelerate the electrochemical anodic reactions and make the oxide layer porous, so that the structurally weak oxide film can be easily removed by mechanical abrasion. The variation of surface roughness and morphology of copper under static conditions is consistent with and provides further support for the reaction mechanisms proposed in the context of DC electro- chemical measurements. In addition, in the presence of H202, 3 vol.% FA/O II may be significantly effective from a surface roughness perspective to obtain a relatively flat copper surface in chemical mechanical planarization （CMP） process.     

基于低温多晶硅薄膜晶体管的AMOLED交流像素电路

This work presents a new voltage programmed pixel circuit for an active-matrix organic light-emitting diode(AMOLED) display.The proposed pixel circuit consists of six low temperature polycrystalline silicon thinfilm transistors(LTPS TFTs),one storage capacitor,and one OLED,and is verified by simulation work using HSPICE software.Besides effectively compensating for the threshold voltage variation of the driving TFT and OLED,the proposed pixel circuit offers an AC driving mode for the OLED,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.     

Efficient Blue Organic Light-emitting Diodes with Simple Structure Based on N,N′-bis （1-naphthyl）-N,N′-biphenyl-1, 1′-biphenyl-4,4′-diamine

Small molecular Organic light-emitting diodes （OLEDs） with high efficiency composed of 2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline （BCP） and N, N%bis-（1-naphthyl）-N, N′,bipheny1-l,1′-biphenyl-4,4′- diamine （NPB） as an electron transporting layer and an emitting layers respectively were studied. Two devices of indium-tin-oxide （ITO）/NPB/BCP/8-hydroxyquinoline aluminum （Alq3）/Mg：Ag and ITO/NPB/BCP/ Mg：Ag with unique simple structure were fabricated. The luminance-voltage and current density-voltage characteristics of devices were investigated. The results demonstrated that the maximum luminance of the double and triple-layer devices is 11500cd/m^2 and 5000 cd/m2 at 15V, respectively. The maximum luminous power efficiency is 1.21m/W at the luminance of 300cd/m^2 and the luminous efficiency of 2.7cd/A. The peak of Electroluminescence （EL） spectrum locates at 433nm and the Commissions Internationale d＇Eclairage （CIE） coordinates are （0.18, 0.17）, which is consistent with the Photoluminescent （PL） spectrum of NPB. The bright blue light emission is independent on the variation of bias voltage. The diversity of device performance with two different structures was discussed.     

Enhanced performance of C60 organic field effect transistors using a tris(8-hydroxyquinoline) aluminum buffer layer

We have investigated the properties of C60-based organic field effect transistors（OFETs） with a tris（8- hydroxyquinoline） aluminum（Alq3） buffer layer inserted between the source/drain electrodes and the active material. The electrical characteristics of OFETs are improved with the insertion of Alq3 film.The peak field effect mobility is increased to 1.28×10^-2 cm²/（V·s） and the threshold voltage is decreased to 10 V when the thickness of the Alq3 is 10 nm.The reason for the improved performance of the devices is probably due to the prevention of metal atoms diffusing into the C60 active layer and the reduction of the channel resistance in Alq3 films.     

Tricolor microcavity OLEDs based on P-nc-Si:H films as the complex anodes

A P+-nc-Si:H film (boron-doped nc-Si:H thin film) was used as a complex anode of an OLED. As an ideal candidate for the composite anode, the P+-nc-Si:H thin film has a good conductivity with a high work function (～5.7 eV) and outstanding optical properties of high reflectivity, transmission, and a very low absorption. As a result, the combination of the relatively high reflectivity of a P+-nc-Si:H film/ITO complex anode with the very high reflectivity of an Al cathode could form a micro-cavity structure with a certain Q to improve the efficiency of the OLED fabricated on it. An RGB pixel generated by microcavity OLEDs is beneficial for both the reduction of the light loss and the improvement of the color purity and the efficiency. The small molecule Alq would be useful for the emitting light layer (EML) of the MOLED, and the P+-nc-Si film would be used as a complex anode of the MOLED, whose configuration can be constructed as Glass/LTO/P+-nc-Si:H/ITO/MoO3/NPB/Alq/LiF/Al. By adjusting the thickness of the organic layer NPB/Alq, the optical length of the microcavity and the REB colors of the device can be obtained. The peak wavelengths of an OLED are located at 486, 550, and 608 nm, respectively.The CIE coordinates are (0.21,0.45), (0.33,0.63), and (0.54,0.54), and the full widths at half maximum (FWHM)are 35, 32, and 39 nm for red, green, and blue, respectively.     

多晶硅薄膜阳极微腔有机发光器件及其简化制备流程的研究

介绍了溶液法金属诱导晶化的p型掺杂多晶硅薄膜(p -poly-Si)的制备,并研究了它的电学特性和光学特性.由于p -MIC poly-Si薄膜具有比较好的电学特性,且在红光区域具有比较高的反射率与透射率和很小的吸收率,因此我们将它用作红光OLED的阳极.结果显示该器件的最大发光效率为5.88cd/A,比用ITO作阳极制备的OLED效率提高了57%.这是由于此薄膜对可见光比较高的反射率和阴极铝对可见光的很高反射性能,使之形成了一定Q值的微腔效应所至.这样,可以实现发光强度较高、单色饱和性较好的单色显示器件.本研究的意义还在于,由于此MOLED的p型掺杂MIC多晶硅阳极是与其共面型驱动TFT有源层、源/漏两极同层材料制备,即是TFT漏极的延伸;这样,不仅形成了高性能的AMOLED单色显示,而且也大大简化了AMOLED工艺流程,从而形成了简化流程的4-mask AMOLED基板制备工艺.     

金属阳极厚度对OLED微腔器件性能的影响

制作了一种以Al为金属反射膜和金属半透膜的微腔有机电致发光器件(OLED)。器件结构是:Al/MoO3/NPB/ADN∶TBPe∶DCJTB/Alq3/LiF/Al。设计了五种厚度的金属Al阳极半透膜器件,Al半透膜的厚度依次为:12nm,13nm,14nm,15nm,16nm。通过调节阳极Al半透膜的厚度,改变微腔的光学长度,研究微腔效应对器件性能的影响。利用Al半透膜阳极厚度的变化,调整微腔器件的光学长度,发光效率和色纯度也随之变化。当Al半透膜为12nm时,器件在11V获得最高亮度3 381cd/m2,最高效率为2.01cd/A,色坐标为(0.33,0.39)。实验表明,合理利用微腔效应,可提高以Al为阳极器件的色纯度,并保持一定的发光效率。     

基于MIC多晶硅薄膜阳极的微腔有机发光器件

通过对溶液法金属诱导晶化多晶硅薄膜制备工艺的优化,制备出性能良好的P型掺杂多晶硅薄膜。厚度为50nm的MICP+-Poly-Si薄膜的方块电阻可降低至400Ω左右,其光学特性表现为在红光区域具有比较高的反射率和很小的吸收率,因此用它替代ITO用作红光OLED的阳极材料。由于此薄膜对可见光比较高的反射率和阴极铝对可见光的高反射性,使之形成了一定Q值的微腔效应。结果显示该器件的最大流明效率为5.88cd/A,比用ITO作阳极制备的OLED提高了57%。进一步优化器件结构,调整发光层在腔中的最佳位置,可以大大增强发光强度,从而可以实现发光强度高、单色性好的红色微腔有机电致发光显示器件。     

利用有机覆盖层提高OLED出光效率

将Alq作为覆盖层真空蒸镀到玻璃基板后制作底发射有机电致发光器件(OLED),所制备的器件结构为:Glass/Alq(xnm)/Al(15nm)/MoO3(30nm)/NPB(60nm)/Alq(65nm)/LiF(1nm)/Al(150nm)。通过研究器件光辐射特性曲线,可以看出覆盖层厚度的变化引起光的干涉效应的变化是导致电致发光变化的原因,广角干涉和多光束干涉之间的相互作用可以通过覆盖层的厚度来调节,并且半透明的Al膜做阳极,将覆盖层蒸镀到阳极之外玻璃基板上,半透明的铝膜和覆盖层与阴极组成微腔器件,通过改变覆盖层的厚度调节微腔的腔长,使OLED电致发光光谱的中心波长发生红移。     

无氧溅射方法制备OLED的ITO透明电极

采用氧化铟锡(ITO)合金材料作为靶材,通过射频磁控溅射制备ITO膜.将获得的ITO膜应用于结构为ITO/m-MTDATA(30 nm)/NPB(20 nm)/Alq3(50 nm)LiF(0.8 nm)/Al(100 nm)的有机电致发光器件(OLED),得到了最大亮度为11560 cd/m2(电压为25V)、最大效率为2.52 cd/A(电压为14 V)的结果.为了获得双面发光,制作了结构为ITO/m-MTDATA(30 nm)/NPB(20 nm)/Alq3(50 nm)LiF(0.8 nm)/Al(20 nm)/ITO(50 nm)的器件,其阳极出光的最大亮度为14460 cd/m2(电压为18V)、最大效率为2.16 cd/A(电压为12V),阴极出光的最大亮度为1 263 cd/m2(电压为19 V)、最大效率为0.26 cd/A(电压为16V).     

高亮度微腔有机电致发光器件

为了实现有机电致发光器件(OLED)发射光谱的窄化和高亮度,真空热蒸镀具有不同微腔结构的OLED(MOLED):玻璃衬底/分布式布拉格反射器(DBR)(1～4对的SiO2/Ta2O5层)/ITO/空穴传输层(HTL,α-NPD)/发光层(EML,Alq3:Rubrene或Alq3:Coumarin6)/电子传输层(ERL,Alq3)LiF/Mg/Ag,其中沉积DBR结构采用电子束沉积法。实验表明:该MOLED的发射光谱半波长宽度(FWHM)随DBR层数的增加而减小至最小值10nm;并且在2层DBR时,掺杂Rubrene器件得到更大的电流效率,约20cd/A,最大亮度为2.6×105cd/m2。研究发现,蓝光MOLED能够对自发光产生吸收现象,降低了出光效率。     

Low-temperature nickel-doped indium tin oxide anode for flexible organic light-emitting devices

Characteristics of an organic light-emitting diode (OLED) with a structure of Al/tris(8-hydroxyquinoline) aluminum (Alq3), N,N′-bis-(1-naphthyl)-N,N′-diphenyl-1, 1′biphenyl-4, 4′-diamine(NPB)/indium tin oxide (ITO)/Arton film have been improved by the introduction of Ni atoms in the ITO surface layer. The threshold voltage and turn-on voltage of an OLED device with Ni sputter power of 90 W and ITO surface oxygen plasma treatment can be reduced, respectively, by 3.4 V and 2.6 V. The existence of Ni atoms and the formation of Ni oxide phases on ITO surface are suggested for the improved characteristics.     

不同玻璃基板对蓝光OLED的影响

文章使用ADN：TBPe作为荧光金属微腔OLED的发光层,以高反射的Al膜作为阴极顶电极,以半透明的Al膜作为阳极底电极,在不同的玻璃基板上制备了结构为Glass/Al（15nm）/MoO3（60nm）/NPB（40nm）/AND：TBPe（30nm,3%）/Alq3（20nm）/LiF（1nm）/Al（140nm）的荧光金属微腔OLED,研究了在普通玻璃及粗化玻璃的粗糙面和平滑面上蒸镀器件时的光学及电学性能影响。实验结果表明,当蒸镀面为光面时,其器件效率及亮度都优于其它器件。     

Spectrum study of top-emitting organic light-emitting devices with micro-cavity structure

Blue and white top-emitting organic light-emitting devices OLEDs with cavity effect have been fabricated.TBADN:3%DSAPh and Alq3:DCJTB/TBADN:TBPe/Alq3:C545 were used as emitting materials of microcavity OLEDs.On a patterned glass substrate,silver was deposited as reflective anode,and copper phthalocyanine (CuPc)layer as HIL and 4'-bis[N-(1-Naphthyl)-N-phenyl-amino]biphenyl(NPB)layer as HTL were made.Al/Ag thin films were made as semi-transparent cathode with a transmittance of about 30%.By changing the thickness of indium tin oxide ITO,deep blue with Commission Internationale de L'Eclairage chromaticity coordinates(CIEx,y)of(0.141,0.049)was obtained on TBADN:3%DSAPh devices,and different color(red,blue and green)was obrained on Alq3:DCJTB/TBADN:TBPe/Alq3:C545 devices,full width at half maxima(FWHM)was only 17 nm.The spectral intensity and FWHM of emission in cavity devices have also been studied.