基于wx-AMPS的锑基双结叠层太阳电池的模拟优化

锑基薄膜太阳电池具有原材料丰富、制备方法简单 和光电性能优异等优势。将宽带隙 Sb₂S₃电池与窄带隙Sb₂Se₃电池组成叠层太阳电池能够进一步提高光谱能量利用率 ,增强器 件性能。基于此,采用wx-AMPS软件对锑基双结叠层薄膜太阳电池进行了仿真优化。仿 真结果显示,要想获得高效的叠层太阳电池首先需要高质量的吸收层,吸收层缺陷态要低于 10¹⁵ cm－3才能够将光生载流子充分转换为电流。除此 之外,子电池厚度的调制能够平衡顶 底电池的光谱响应,在叠层太阳电池的优化中也十分重要。基于此,绘制了不同顶底电 池厚度叠层太阳电池性能参数的等高线图,为叠层太阳电池的实验优化制备提供指导,并最 终在顶底电池厚度分别为700 nm和2500 nm的情况下,得到24.60%的锑基双结叠层太阳电 池 的最高光电转换效率。研究结果体现了新型锑基薄膜叠层太阳电池结构的优势和发展 潜力。     

Ti掺杂对Sb2Te3薄膜的结构及光学性质的调控

对Sb₂Te₃薄膜的结构、线性光学及非线性吸收性质的Ti掺杂影响进行了系统性探究。利用磁控溅射和高温退火手段制备了不同Ti掺杂浓度的晶态Sb₂Te₃薄膜。X射线光电子能谱分析显示Sb₂Te₃薄膜中的Ti元素以Ti⁴⁺化学态以TiTe₂的形式存在。线性光学性质结果表明,在保持非线性器件中宽工作波长特性的同时,Ti掺杂可以提高Sb₂Te₃薄膜的透射率,并降低光学带隙从1.32 eV至1.25 eV,根据Burstein-Moss理论,这取决于载流子的减少。利用自主搭建的开孔Z扫描系统,测试了薄膜样品在132 GW/cm²强度下800 nm飞秒激光激发的非线性吸收性质,结果显示的Ti掺杂引起的饱和吸收可调谐行为可归因于光学带隙减小与晶化抑制的竞争效应。此外,Ti掺杂将Sb₂Te₃薄膜的激光损伤阈值从188.6 GW/cm²提高到了265.5 GW/cm²。总而言之,Ti掺杂Sb₂Te₃薄膜在非线性光学器件领域具有广泛的应用前景。     

沉积预制层衬底温度对CIGS薄膜结构特性的影响

采用三步共蒸发工艺在玻璃衬底上制备CIGS薄膜, 研究沉积预制层的衬底温度对CIGS薄膜 结构特性的影响。薄膜的厚度、组份、晶相结构、表观形貌和电学特性分别由台阶仪、X射 线荧光光谱(XRF)、X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)和霍耳效应测量仪来表征。沉积 预制层的衬底温度 较低(如300℃)时,预制层中Ga含 量较低,容易形成In₂Se₃相;而衬底温度较高(如400℃) 时,预制层中Ga含量较高,容易形成(In,Ga)₂Se₃相;原因是Ga₂Se₃的形成焓(－462.4kJ/mol)比In₂Se₃的(－360kJ/mol)低,没有In₂Se₃稳定;In₂Se₃相比Ga₂S e₃相更容易稳定存在,尤其是在低温下;当温度较高 时,Ga₂Se₃相也容易存在,与In₂Se₃一起形成(In,Ga)₂Se₃固溶体。而且,衬 底温度较高(如400℃)时,沉积 的CIGS薄膜中的Ga含量比其它两种衬底温度下沉积的薄膜都高,薄膜粗糙度较小,迁移率和 载流子浓度都比较大,电阻率较小。     

稀土Er掺杂的MoSe2纳米线的制备及发光特性研究

本文研究了稀土掺杂硒化钼(MoSe₂)垂直纳米线 的制备及光学特性。以分析纯硒化钼 粉末为原料,采用热蒸发方法在Si衬底上沉积硒化钼垂直纳米线,并在其生长过程中利用硝 酸鉺进行原位掺杂。利用原子力显微镜(AFM)、X射线衍射仪(XRD)、紫外-可见分光光度计 和 荧光光谱仪研究了掺杂硒化钼薄膜的表面形貌﹑晶体结构﹑光吸收和特性。发现掺杂后MoSe ₂纳米线的结晶性更强,长度增加2倍以上。同时,掺杂后纳米线的可见光吸收和光致发光 强 度明显增强,760 nm处MoSe₂纳米线的带间跃迁的本征发射增强4倍 以上。另外,Er³⁺掺杂后 ,在590 nm和650 nm处增加了2个来自Er³⁺离子的发射,说明稀土掺杂后发光峰增加,使 光谱谱线更加丰富。以上结果表明,稀土掺杂可显著增强硒化钼的结晶性、光吸收和发光效 率,使其可用于制备超薄、高效率的太阳能电池、光探测器等光电子器件。     

衬底温度对ITO/Ga2O3深紫外透明导电薄膜性能的影响

用磁控溅射的方法在石英玻璃上制备了ITO/Ga₂O₃双层膜。用X射线衍射仪、扫描电镜、双光束分光光度计和霍尔效应测试仪研究了衬底温度对ITO/Ga₂O₃双层膜的结构、表面形貌、光学性能和电学性能的影响。双层膜结构受衬底温度的影响,当衬底温度从100C 升高到 350C时,薄膜的电阻率由6.71′10^-3 Ω.cm 降到 1.91′10^-3 Ω.cm。衬底温度300C制备的ITO(22nm)/Ga₂O₃(50nm)双层膜的面电阻为373.3Ω,在300nm波长的深紫外透过率为78.97%。     

利用偏钨酸铵的DMF/水溶液旋涂热解制备WO3薄膜及其在钙钛矿太阳电池致密层中的应用

本文首次通过旋涂热解偏钨酸铵((NH₄)₆H₂W₁₂O₄₀)的DMF/水溶液成功制备了致密的三氧化钨(WO₃)薄膜, 系统研究了WO₃薄膜厚度及用异丙醇冲洗处理气相辅助溶液法制备的CH₃NH₃PbI₃薄膜对相应钙钛矿太阳电池光伏性能的影响. 结果表明, 使用厚度为62nmWO₃致密层的平板钙钛矿太阳电池获得了短路电流密度17.39 mA.cm_-2, 开路电压0.58 V, 填充因子0.57, 相应光电转化效率5.72%. 使用异丙醇冲洗CH₃NH₃PbI₃薄膜后, 相应太阳电池的光电转化效率由5.72 % 升高到7.04 %.     

脉冲激光沉积Er:LiNbO3薄膜及1.54μm光致发光的研究

利用脉冲激光沉积(PLD)技术,通过双靶(Er₃O₂/LiNbO₃)交替与脉冲激光作用,在SiO ₂/Si 衬底上制备了c-轴择优取向的Er掺杂LiNbO₃(Er:LiNbO₃)薄 膜。用X射线衍射(XRD)、 场发射扫描电子显微镜(FESEM)、台阶仪及光致发光(PL)光 谱对制备的掺杂薄膜进行了表征。研究了衬底温度、O₂压及沉积时间对Er:LiNbO₃薄膜 结晶、表面形貌及 PL性能的影响。结果发现,衬底温度低于300℃时制备的Er:LiNbO 3薄膜为非晶膜,随衬底温度升高,薄膜出 现(006)衍射峰,并且其强度随衬底温度升高而增大;O₂压变化对 利用双靶沉积获得的Er:LiNbO₃薄膜择优 取向及(006)衍射峰强度影响不明显;沉积时间越长Er:LiNbO₃薄膜 中Er³⁺浓度越大,但结晶择优取向 变差;利用532nm波长激光泵浦,室温下,在1537nm波长处测得很强的光致荧光峰,而且沉积时间越长谱峰越尖锐强 度越大。     

RF-PECVD法制备高Ge含量微晶Si-Ge薄膜及太阳电池

采用射频等离子体增强化学气相沉积 (RF-PECVD) 技术,研究了衬底温度对高Ge 含量(≈50%)微晶Si-Ge(μc-SiGe:H)薄膜结构特性 和电学特性的影响。结 果表明:较低的衬底温度会抑制 μc-SiGe:H薄膜(220)晶向的择优生长;而当衬底温度过高 时,μc-SiGe:H薄膜的O含量和微 结构因子较大。在衬底温度为200℃时,获得了光电特性和结构特性 较优的高Ge含 量μc-SiGe:H薄膜。将优化好的μc-SiGe:H薄膜应用到电池中,在本征层 为600nm的情况下, 获得了转换效率为3.31%(J_sc=22.5mA/cm²,V_oc=0.32V,FF=0.46)的单结μc-Si Ge:H电池,电池在1100nm处的光谱响应 达5.49%。     

脉冲Nd:YAG激光器选区晶化制备多晶硅薄膜

采用三倍频后的Nd:YAG固体脉冲激光系统(波长为355 nm)选区诱导晶化非晶硅薄膜,以制备多晶硅薄膜。分别测试了激光晶化前后薄膜的表面形貌和拉曼光谱。在文中分析了400 nm厚薄膜在激光扫描前后的表面形貌变化。拉曼光谱显示薄膜的晶化程度随着激光能量的增加而提高。最优的激光晶化能量密度与薄膜的厚度相关。对于300 nm和400 nm厚的非晶硅薄膜,有效晶化非晶硅的能量密度分别在440-634 mJ/cm²,777-993 mJ/cm²之间。在激光能量密度分别为634 mJ/cm²,975 mJ/cm²和1571 mJ/cm²时,300 nm、400 nm和500 nm厚薄膜达到最好的晶化效果。     

沉积气压对脉冲激光沉积CNx薄膜结构和摩擦学特性的影响

以脉冲激光沉积(PLD)的CNx材料为靶源,以单晶Si片为衬底,在N₂气压为2～11Pa 下PLD制备了CNx薄膜。采用X射线光电子能谱(XPS)、拉曼 (Raman)光谱、扫描 电子显微镜(SEM)和球盘式摩擦磨损试验机分别对薄膜的化学成分、价键状态、表面形貌和 摩擦性能进行了表征。结果表明:低沉积气压导致薄膜N含量的退化及耐磨性能的下降;沉 积气压介于5～8Pa时最利于sp³杂化键的形成,且薄 膜的N含 量缓慢下降,膜中比值x_sp²/x_sp³和ID/IG均减 小,x_sp²C-N/x_sp³C-N增加并趋于恒定,薄膜的耐磨性较好(约2.7～4.3×10 －15 m³·N－1·m－1),但摩擦系数相对较高(约0.24～0.25);过高的气压导致膜层中 N含量的下降和石墨化程度的增加,薄膜摩擦系数较低(约0.19), 但耐磨性呈下降趋势。     

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.