用生长/氢等离子体交替处理堆积层表面技术制备微晶硅薄膜

利用HW-MWECR CVD系统,用氢等离子体处理间隙生长堆积层表面技术,制备了一系列不同厚度的μc-Si:H薄膜.发现,当薄膜厚度在0.55μm以下时,样品具有较为典型的非晶硅特征,光电导衰退率很大;当薄膜厚度为0.60～0.70μm之间时,样品兼备非晶和微晶的特点,在这一厚度范围内,光电导随薄膜厚度变化非常敏感,光电导衰退率较小;当薄膜厚度为0.80μm以上时,薄膜表现为明显的微晶硅性质,其光电导衰退率很小,通过模拟光照53.5h,其光电导几乎不变化.     

器件质量级微晶硅薄膜光稳定性研究

利用射频等离子体增强化学气相沉积（RFPECVD）技术，通过改变SiH4浓度制备了一系列不同晶化率（Xc）的本征Si薄膜材料。通过测量其Raman谱和光、暗电导率（σph、σd）研究了工艺变化对材料结构的影响及材料光电特性同微观结构的关系，然后对样品进行老化实验，测量其光照前后的吸收系数α及量子效率、迁移率和寿命的乘积nμτ。分析其光照前后光电性能的变化规律结果表明，相变域附近的微晶硅（μc-Si：H）薄膜材料适合制备μc-Si2H太阳电池；结合退火实验的结果发现，μc-Si：H材料中的非晶成分是导致微晶材料光电特性衰退的主要原因。     

厚度对a—Si：H薄膜性能的影响

用等离子体增强化学气相沉积法在最佳工艺参数下在硼玻璃基片上沉积了厚度为1μm以下的不同厚度的a-Si:H薄膜。测量了薄膜厚度对它的光电性质的影响。结果表明，当膜厚增加时，a-Si:H薄膜暗电导、光电导和阈值电压增大，光学带隙和Raman谱的TA模与TO模峰值比减小，折射率几乎不变，光吸收系数和通断电流比先增大，达到最大值后又减小。     

微晶硅薄膜微结构对稳定性的影响

实验研究了不同晶化率的微晶硅（μc-Si）薄膜的光衰退现象,提出了制备高稳定性硅薄膜太阳电池材料选取方案。研究结果表明,μc-Si中的非晶硅（a-Si）组分是导致光衰退的主要原因,晶化率越高,材料越稳定;过渡区靠近μc-Si材料区域的μc-Si材料,由于具有更好的稳定性和光敏特性,适于制备μc-Si太阳能电池;过渡区附...     

弱硼掺杂补偿对氢化微晶硅薄膜制备与特性的影响

研究了弱硼掺杂补偿对甚高频等离子体增强化学气相沉积方法生长氢化微晶硅薄膜(μc-Si:H)及材料特性的影响.实验发现,随着弱硼补偿剂量的增大,μc-Si:H薄膜的沉积速率先减小后增加,变化范围约为0.7～0.8nm/s.相比较而言,材料的结晶度以及晶粒的平均颗粒尺寸则呈现出先增后减的变化,且变化的幅度较大,当弱硼补偿剂量大于2.5ppm时,过度的弱硼补偿将导致μc-Si:H薄膜的结晶状况恶化.此外,光敏性、暗电导及电导激活能的测量结果进一步表明,弱硼补偿显著影响μc-Si:H薄膜的光电特性,弱硼补偿剂量为2.5ppm左右时,材料的光电特性最为理想.因此,优化弱硼补偿剂量是获得器件级质量μc-Si:H材料的有效途径.     

弱硼掺杂补偿对氢化微晶硅薄膜制备与特性的影响

研究了弱硼掺杂补偿对甚高频等离子体增强化学气相沉积方法生长氢化微晶硅薄膜（μc-Si∶H）及材料特性的影响.实验发现,随着弱硼补偿剂量的增大,μc-Si∶H薄膜的沉积速率先减小后增加,变化范围约为0.7～0.8nm/s.相比较而言,材料的结晶度以及晶粒的平均颗粒尺寸则呈现出先增后减的变化,且变化的幅度较大,当弱硼补偿剂量大于2.5ppm时,过度的弱硼补偿将导致μc-Si∶H薄膜的结晶状况恶化.此外,光敏性、暗电导及电导激活能的测量结果进一步表明,弱硼补偿显著影响μc-Si∶H薄膜的光电特性,弱硼补偿剂量为2.5ppm左右时,材料的光电特性最为理想.因此,优化弱硼补偿剂量是获得器件级质量μc-Si∶H材料的有效途径.     

厚度对a-Si∶H薄膜性能的影响

用等离子体增强化学气相沉积法在最佳工艺参数下在硼玻璃基片上沉积了厚度为1 μm以下的不同厚度的a-Si∶H薄膜.测量了薄膜厚度对它的光电性质的影响.结果表明,当膜厚增加时,a-Si∶H薄膜暗电导、光电导和阈值电压增大,光学带隙和Raman谱的TA模与TO模峰值比减小,折射率几乎不变,光吸收系数和通断电流比先增大,达到最大值后又减小.     

薄膜厚度对直流溅射制备AZO薄膜的特性影响

采用直流磁控溅射法,当衬底温度为室温时,在普通玻璃衬底上制备出了低电阻率、高透过率的ZnO:Al透明导电薄膜.研究了薄膜厚度对薄膜结构以及光电特性影响.当薄膜厚度为930 nm,薄膜的光电特性最好,电阻率为4.65×10~(-4)Ω·cm,可见光范围内的平均透过率为85.8%,禁带宽度约为3.51 eV.     

高压高功率VHF-PECVD的微晶硅薄膜高速沉积

采用高压高功率(hphP)甚高频等离子体强强化学气相沉积(VHF-PECVD)法对微晶硅(μc-Si:H)进行高速沉积,在最优沉积条件参数下对hphP和低压低功率(lplP)两组样品沉积速率、光电导、暗电导及光敏性等性能参数进行测试,得到了1.58 nm/s的较高沉积速率、光电性能优秀和更适合薄膜太阳能电池的μc-Si...     

直流磁控溅射法制备YBCO超导薄膜研究

文中采用直流磁控溅射法制备了YBCO超导薄膜,研究了镀膜过程中不同的气体总压、氧氩比、薄膜厚度以及退火温度对薄膜性质的影响,通过XRD分析,当总气压为40Pa、氧氩比为1：2、厚度为1μm、退火温度为800℃时,是薄膜生长的最佳条件。总气压过低,镀膜过程不能进行,气压过高,分子间自由程增加,溅射速率降低;氧氩比较低时,...     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.