双阴极修饰层改善Rubrene/C70有机太阳能电池的性能

采用NTCDA/PTCBI双阴极修饰层制备了结构为ITO /MoO₃/Rubrene/C70/NTCDA/PTCBI/Al有机太阳能 电池(OSC),研究了双阴极修饰层对Rubrene/C70 OSC性能的影 响。实验结果表明,引入双阴极修饰层 后,器件的各性能参数有了显著提高。通过对PTCBI厚度优化发现,当PTCBI厚为5nm时器件 的各性 能参数最佳,器件的功率转换效率(PCE)=3.19%,电流密度Jsc=8.99mA·cm－2,开路电 压Voc=0.85V, 填充因子(FF)=41.58%,与未插入PTCBI 层相比器件的各性能分别提高了538%、338.5% 、13.3%和16.5%。     

基于PIN结构的Rubrene/C_(70)太阳能电池的性能研究

实验制备了ITO/V2O5/Rubrene/C70:Rubrene/C70/BCP/Al的PIN结构有机太阳能电池(OSC),其中Rubrene、Rubrene:C70和C70分别作为P、I和N层。通过改变I层厚度,研究了I层对OSC性能的影响及作用机理。实验显示,I层厚为5nm时器件的功率转换效率η达到最大值为1.580%,同时获得了较大的短路电流密度Jsc为4.365mA·cm-2;相对PN结构器件,功率转化效率η短路电流密度Jsc和填充因子FF分别提高了40.3%、29.7%和8.2%。我们认为,I层中激子分离效率的提高导致了器件性能的改善。     

WO3对Rubrene/C70有机太阳能电池性能的改善

研究了WO₃对Rubrene/C₇₀有机太阳能电池 (OSCs)性能的 改善,制备了结构为ITO/WO₃/Rubrene/C₇₀/BCP/Al的OSCs,其中WO₃插入在I TO和Rubrene中间作为阳极修饰层。通过优化WO₃的厚度,研究了WO₃对OSCs性能的改善及其作用机理。实验发现,器件的短路电流Jsc、开路电压V_oc、 填充因子(FF)、光电转换效率(PCE)和串联电阻Rs等性能参数随WO₃厚度的变化呈规律性变化;当 WO₃厚度小于80 nm时,器件PCE随着厚度的增加不断增大;当W O ₃厚大于80 nm时,器件PCE随着厚度的 增加不断减小;当WO₃厚度为80 nm 时,器件PCE达到最高为1.03%, 相应的J sc、V_oc、FF分别为2.81mA·cm－2、 0.83V、43.85%,Rs为45.3Ω·cm²,对比没有WO₃修饰层, 器件的J_sc、V_oc、FF和PCE分别提高了31%、137%、17%,Rs降低了33%。     

ZnO缓冲层改善Rubrene/C70有机太阳能电池的性能

通过制备结构为ITO/ZnO/C₇₀ /Rubrene/MoO₃/Al 的有机太阳能电池(OSCs),研究了ZnO作为阴极 修饰层对Rubrene/C70有机太阳能电池性能的改善。同时通过 优化ZnO的厚度研究了ZnO的工作机理。 从实验结果可以看出,随着ZnO厚度的变化,器件的短路电流密度(J_sc)、开路电压(V_oc)、填充因子 (FF)、光电转换效率(PCE)和串联电阻(R_s)等性能参数呈现出了规律 性变化,当ZnO层厚度比较 薄时,器件PCE随着厚度的增加不断增大,当ZnO层厚度为53nm时,器件PCE达到最高为1.13%, 对应的J_sc、V_oc、FF分别为2.82mA·cm－2、0. 84V、45.86%,R_s为66.2Ω·cm²,当ZnO层厚度继续增 加时,器件PCE开始减小。对比没有ZnO阴极修饰层,器件最优时 的Jsc、V_oc、FF和PCE 分别提高了49%、17%,R_s降低了56%。     

热处理对Rubrene/C70有机太阳能电池性能的改善

制备了ITO/MoO3(6nm)/Rubrene(30nm)/C70(30nm)/BCP(6nm)/Al(150nm)的PN结构和ITO/MoO3(5nm)/Rubrene(25nm)/Rubrene:C70(5nm)/C70(25nm)/BCP(6nm)/Al(150nm)的PIN结构有机太阳能电池(OSCs)。通过对两种器件进行热处理,研究热处理对OSCs性能的影响。实验表明,在热处理后,PN结构和PIN结构器件的短路电流密度分别达到了3.526mA·cm-2和5.413mA·cm-2,功率转换效率分别达到了1.43%和2.09%。与未经过热处理的器件相比,PN结构和PIN结构器件的短路电流密度、填充因子、功率转换效率分别提高了19.0%、7.1%、28.3%和4.8%、20%、24.1%。可见,热处理可以提高Rubrene/C70OSCs的性能。     

低温处理的TiO2纳米颗粒薄膜作为缓冲层的有机光伏电池

通过溶胶凝胶法(sol-gel)合成了TiO₂纳米颗 粒(NPs),制备了结构为 ITO/PEDOT:PSS/P3HT:PCBM/TiO₂/Al的有机太阳能电池(OSC)器件。通过优化阴极缓冲 层TiO₂NPs的 热处理温度,考察了温度以及溶剂对TiO₂NPs薄膜的光学性能、形貌结构和电学 性能的影响,并研究了其对OSC性能的影响及作用机理。实验发现,TiO₂NPs处理温度 为80℃时,器件 的效率达到了2.52%。相对于参比器件,器件的光电转换效率(PCE) 、填充因子(FF)分别提高了60%、64.7%。     

正置倒置异质结有机小分子太阳能电池

以MoO3为阳极修饰层,以Rubrene/C60为活性层,制备了正置和倒置异质结有机小分子太阳能电池。实验结果表明倒置器件的开路电压Voc、短路电流密度Jsc、填充因子FF和功率转换效率η比正置结构的器件分别提高了34%、20%、25%和102%。当插入BCP阴极缓冲层后,阻挡了热的Al原子对C60层的破坏,对倒置器件的性能没有明显的影响,但却显著改善了正置器件的性能,并分析了MoO3和BCP对倒置和正置器件的作用。     

基于DOPPP的高效白光OLED器件

采用真空热蒸镀的方法,以荧光染料1-(2,5-d imethoxy-4-(1-pyrenyl)-phenyl)pyrene (DOPPP)为蓝发光 层,5,6,11,2-Tetraphenylnaphthacene (Rubrene)为黄发光层,制备了结构为ITO/m-M TDATA(10nm)/NPB(30nm)/ Rubrene (0.2nm)/ DOPPP (x nm)/TAZ(10nm)/Alq₃(30nm)/LiF(0.5nm)/Al的双发光层的高效白色有机电 致发光器件(OLED)。通过调整DOPPP层的厚度,研究器件的发光性能。当DOPPP层厚小 于25nm时,器件以 黄光发射为主;当DOPPP层厚为25nm时器件的性能最佳,在电流密度为209.18mA/cm²时,获得最 大亮度为9232cd/m²,在电流密度为103.712mA/cm²时获得最大电流效率4.68cd/A, 并随着驱动电压 的升高,器件的色坐标从(0.366,0.365)变化到(0.384,0.399),都在白光的范围之内;当DOPPP层厚度超过25nm时,器件的效率和亮度 都开始下降。     

Bathocuproine作为缓冲层改善Rubrene/C70太阳能电池的性能

制备了结构为ITO/Rubrene/C70/BCP/Al的双层有机太阳能电池(OSCs),通过优化缓冲层BCP的厚度研究了BCP对OSCs性能的影响及其作用机理。实验发现,BCP厚为6nm时,器件的效率最高达到1.78%,同时获得了较大的开路电压0.901V。相对于没有缓冲层,器件的效率、短路电流、开路电压和填充因子分别提高了432.9%、74.8%、95.4%和55.5%。     

基于CdSe/ZnS和Alq3的白光量子点LED的研究

采用CdSe/ZnS红光量子点(QD),利用旋涂和真 空蒸镀工艺制备了结构为ITO/TPD+PVK/QDs/Alq₃/LiF/Al的量 子点发光器件(QD-LED),并对器件的发光性能做了测试。研究了ITO表面处理、TPD空穴 传输层和QD发光层的厚 度对QD-LED性能的影响,并通过调整QD发光层和Alq₃电子传输层的 厚度,制备了可用于照明 的白光QD-LED。实验结果表明,ITO的表面处理可有效降低器件的开启电压,开启 电压从9V降到7V左右; TPD空穴传输层和QD发光层的厚度对器件的电流密度和发光亮度有较大的影响,而Alq₃电 子传输层和QD发光层 的合理配比可以混合出较高色温的白光。通过优化器件各参数,当TPD和PVK质量比为5∶1、QD度为1.0mg/ml和 Alq₃厚为60nm时,制备的器件在15V电压 时发光效率达到了1500c d/m²,色坐标为(0.3628,0.3796) ,显色指数为88.1。     

VOLTE容灾机制研究及优化方案

_{本文首先对VOLTE现网网络结构及容灾机制进行研究分析,发现现存容灾机制中存在的缺点和不确定性,针对其中的问题,针对性地进行了深入研究和分析,创新的提出了1种快速容灾抢通方案,以达到提升VOLTE业务运维能力和用户业务感知的目的。}     

Calculation of energy band gaps in quaternary iii/v alloys

The dielectric theory of electronegativity is applied to the calculation of the compositional dependence of the energy band gap for quaternary III/V alloys of type A_l-xB_xC_1-yD_y and A_1-x-yB_xC_yD. The departure from linearity of E_G versus x and y is taken to be the sum of two terms, the intrinsic or virtual crystal term and the extrinsic term due to effects of aperiodicity which for one type of alloy may occur on both sublattices. Rather than simply treating the quaternary as an average of the bounding ternary systems, as has been common in the past, the intrinsic departure from linearity is calculated by assuming E_h,i,C, and D_av to vary linearly with x and y. The result is a smaller intrinsic deviation from linearity and a much better fit to existing data in the system Ga_1-xIn_xAs_1-y P_y. The calculation is also applied to three systems where no data exist but which are of great interest because of their potential application for the fabrication of lattice matched tandem solar cells: Ga_l-xA1_xAs_l-ySb_y. Ga_1-x-yA1_xIn_yAs, and GaAs_1-x-yP_xSb_y.     

新形势下河北移动全业务支撑策略研究

随着铁塔公司的成立及国家在“宽带中国”“提速降费”等一系列通信领域的重大战略实施,全业务运营越来越成为河北移动保持领先,实现卓越的重要支点。基于此河北移动启动大规模综合业务区建设,由传统传输网围绕基站建设转向全业务支撑。河北移动将综合业务区建设与全业务机房的选取统筹安排,建设综合业务区与全业务机房的联络光缆,将综合业务区光缆网成为承载重要集客数据专线和4G拉远站的载体,合理、有序、迅速实现“一张光缆网”的建设,鼎力支撑全业务及4G的发展。     

Nickel silicidation techniques for strained Si1?xGex, Si1?x?yGexCy, and Si1?yCy alloys material-device applications

A nickel silicide process for Si_1-xGe_x, Si_1-x-yGe_xC_y, and Si_1-yC_y alloy materials compatible with Si technology has been developed. Low-resistivity-phase (12–20 μΘ cm) nickel silicides have been obtained for these alloys with different low sheet-resistance temperature windows. The study shows that thin (15–18 nm) silicide layers with high crystalline quality, smooth silicide surface, and smooth interface between silicide and the underlying material are achievable. The technique could be used to combine the benefits of Ni silicide and Si_1-xGe_x, Si_1-x-yGe_xC_y, and Si_1-yC_y alloys. The technique is promising for Si or Si_1-xGe_x, Si_1-x-yGe_xC_y, and Si_1-yC_y alloy-based metal-oxide semiconductor, field-effect transistors (MOSFETs) or other device applications.     

Low pressure metalorganic chemical vapor deposition of InP and related compounds

The low pressure metalorganic chemical vapor deposition epitaxial growth and characterization of InP, Ga_0.47In_0.53 As and Ga_xIn_1-xAs_yP_1-y, lattice-matched to InP substrate are described. The layers were found to have the same etch pit density (EPD) as the substrate. The best mobility obtained for InP was 5300 cm² V⁻¹S⁻¹ at 300 K and 58 900 cm² V⁻¹ S⁻¹ at 77₂K, and for GaInAs was 11900 cm² V⁻¹ S⁻¹ at 300 K, 54 600 cm² V⁻¹ S⁻¹ at 77 K and 90 000 cm V⁻¹S⁻¹ at 2°K. We report the first successful growth of a GaInAs-InP superlattice and the enhanced mobility of a two dimensional electron gas at a GaInAs -InP heterojunction grown by LP-MO CVD. LP MO CVD material has been used for GaInAsPInP, DH lasers emitting at 1.3 um and 1.5 um. These devices exhibit a low threshold current, a slightly higher than liquid phase epitaxy devices and a high differential quantum efficiency of 60%. Fundamental transverse mode oscillation has been achieved up to a power outpout of 10 mW. Threshold currents as low as 200 mA dc have been measured for devices with a stripe width of 9 um and a cavity length of 300 um for emission at 1.5 um. Values of T in the range 64–80 C have been obtained. Preliminary life testing has been carried out at room temperature on a few laser diodes (λ = 1.5μm). Operation at constant current for severalthousand hours has been achieved with no change in the threshold current.     

Transport properties of thermoelectric materials for coolers

The Seebeck coefficient, thermal conductivity, electrical conductivity and Hall coefficient of cooler grade, p-and n-type ternary alloys of Bi₂Te₃-Sb₂Te₃-Sb₂Se₃ were measured between 10 and 300 K. Between 300 K and about 150 K the temperature dependence of the transport properties can be explained by assuming nondegeneracy and a lattice scattering mechanism. The difference between the temperature dependence of the Hall effect in n-and p-type alloys can be explained by the presence of sub-bands of light and heavy holes in the valence band of p-type alloys.     

Characterization of a rapid thermal anneal TiNxOy/TiSi2 contact barrier

In this paper, the physical and electrical properties of a TiN_xO_y/TiSi₂ dual layer contact barrier are reported. The TiN_xO_y/TiSi₂ barrier was formed by rapidly annealing a Ti thin film on Si in an N₂ ambient. During this process, the Ti film surface reacts with N₂ to form a TiN_xO_y skin layer and the bulk of the Ti film reacts with Si to form an underlying TiSi₂ layer. The influences of rapid thermal anneal (RTA) conditions on the TiN_xO_y layer were investigated by varying the RTA temperature from 600 to 1100° C and cycle duration from 30 to 100 s. It is found that the resulting TiN_xO_y and TiSi₂ layer thicknesses are dependent on RTA temperature and the starting Ti thickness. For a starting Ti thickness of 500Å, 150Å thick TiN_xO_y and 800Å thick TiSi₂ are obtained after an RTA at 900° C for 30 s. The TiN_xO_y thickness is limited by a fast diffusion of Si into Ti to form TiSi₂. When a Ti film is deposited on SiO₂, Ti starts to react with SiO₂ from 600° C and a significant reduction of the SiO₂ thickness is observed after an RTA at 900° C. The resulting layer is composed of a surface TiN_xO_y layer followed by a complex layer of titanium oxide and titanium suicide. In addition, when Ti is depos-ited on TiSi₂, thicker TiN_xO_y and TiSi₂ layers are obtained after RTA. This is because the TiSi₂ layer retards the diffusion of Si from the underlying substrate into the Ti layer. NMOSFETs were fabricated using the TiN_xO_y/TiSi₂ as a contact barrier formed by RTA at 900° C for 30 s and a significant reduction of contact resistance was obtained. In addition, electromigration test at a high current density indicated that a significant improvement in mean time to failure (MTF) has been obtained with the barrier.     

Processing of large YBa2 Cu3Ox domains for levitation applications by a Nd1+x Ba2−x Cu3 Oy-Seeded melt-growth technique

YBa₂Cu₃O_x domains for levitation applications have been produced by a seeding technology that includes Nd_1+x Ba_2−x Cu₃O_y seeds and melt-processing technologies such as conventional melt-textured growth, melt-texturing with PtO₂ and Y₂BaCuO₅ additions, and the new solid-liquid-melt-growth technology. Large domains (∼20 mm) with high levitation forces (F₁ up to 8.2 N) have been produced. The reproducibility of the results is good, and the capability of producing a large number of pellets in a single batch indicates good potential for the production of large amounts of this material.     

基于InP衬底的晶格失配In0.68Ga0.32As的MOCVD生长及其特性研究

采用MOCVD生长技术在InP衬底上成功实现了晶格失配的3μm In0.68 Ga0.32As薄膜生长.通过As组分的改变,利用张应变和压应变交替补偿的InAsxP1-x应变缓冲层结构来释放由于晶格失配所产生的应力,在InP衬底上得到了与In0.68Ga0.32 As晶格匹配的InAsxP1-x“虚拟”衬底,通过对缓冲层厚度的优化,使应力能够在“虚拟”衬底上完全豫弛.通过原子力显微镜(AFM)、高分辨XRD、透射电镜(TEM)和光致发光(PL)等测试分析表明,这种释放应力的方法能够有效提高In0.68 Ga0.32 As外延层的晶体质量.     

The effect of Tl2Te3 on the properties of the solid solution (Sb2Te3)0.75.(Bi2Te3)0.25

The effect on transport properties of the addition of 0.5-5% Tl₂Te₃ to p-type solid solutions of antimony and bismuth tellurides was studied. It was found that the addition of Tl₂Te₃ caused a lessening of the increase of hole concentration as low temperatures were approached, resulting in a slower decrease of the Seebeck coefficient with a decrease in temperature. In partial fulfillment of M.Sc. degree, Hebrew University, Jerusalem. Permanent address, Dept. of Inorganic and Analytical Chemistry, Hebrew University, Jerusalem.