电子束辐照剂量对PAN/PEO交联度的影响

对PAN/PEO凝胶(5%PAN,5%PEO)在1.0 MeV电子束下进行了不同剂量的辐照。红外光谱测量表明,PAN/PEO凝胶辐照后发生了化学交联。分析结果指出,PAN/PEO的凝胶分数随着辐照剂量的增加而不断增加;其凝胶分数增长率的变化可以分为3个阶段,即快速增加阶段(0~39kGy)、下降阶段(39~130 kGy)和稳定阶段(130 kGy)。拟合发现,引入材料刚性参数β的半经验修正方程与未考虑材料刚性的Char1esby-Pinner方程相比,更符合实际测量值(对于该配比PAN/PEO,β为0.166)。交联度-辐照剂量曲线显示,交联度随辐照剂量的增加而增加,为设计新型能功能材料中所需的固定交联度的PAN/PEO凝胶提供了辐照剂量参考值。     

电解质中添加氧化物颗粒对染料敏化太阳电池性能的增强

"在液态电解质中加入纳米TiO2、微米TiO2、Al2O3和ZrO2颗粒后,在一定的氧化物含量下,都不同程度地提高了DSC的光电特性,而以加入12.5%的纳米TiO2 (P25)得到最高的提高,达到5.5%,比没有加入氧化物颗粒的DSC效率提高达到51%以上．利用电化学阻抗谱和循环伏安法研究了在染料敏化太阳电池液态电解质中加入各种氧化物颗粒对电池电解质特性的影响,结果发现,加入氧化物颗粒后,由于界面效应,提供了I3-的快速扩散通道,从而I3-扩散系数得到较大提高,电解质/Pt电极间的电荷传输电阻下降,改善     

聚苯胺基固态染料敏化太阳电池中电子输运性能的研究

以导电聚苯胺为空穴传输材料，制备了固态染料敏化太阳电池(DSC).利用强度调制光电流谱(IMPS)和强度调制光电压谱(IMVS)研究了TiO₂多孔膜内的电子输运及复合过程.通过TiO₂多孔膜内电子的平均传输时间(τ_d)和电子寿命(τ_n)及对IMPS实验数据的拟合，获得电子在TiO₂膜内的有效扩散系数(D_n)和扩散长度(L_n).这些聚苯胺基电池中的τ_n值为相应的液体型电池的1/10倍左右，表明在该固体电池中存在严重的光生电子的复合过程，这很可能主要是与氧化态染料分子和导电电子间的复合有关.随着TiO₂膜厚的增加，τ_n和τ_d均变小，但D_n和L_n随之增加，只有在合适的膜厚范围内才能获得较高的光伏性能. 关键词： 聚苯胺 染料敏化太阳电池 IMPS IMVS     

染料敏化太阳电池及其进展

文章介绍了染料敏化太阳电池的研究背景和发展过程,简述了基于纳米TiO2半导体电极材料的染料敏化太阳电池的基本结构和工作机理.详细阐述了该电池国内外各项关键技术的实验和产业化研究最新成果,着重分析了染料敏化太阳电池的未来发展趋势,并对该电池的应用前景进行了展望.     

TiO2颗粒尺寸对染料敏化太阳电池内电子输运特性影响研究

采用强度调制光电流谱(IMPS)和强度调制光电压谱(IMVS)研究了染料敏化太阳电池(DSC)内部电子传输和背反应动力学特性.在纳米TiO2薄膜厚度相同的情况下,借助于IMPS/IMVS测量了由3种不同TiO2颗粒尺寸大小薄膜制备出DSC的电荷传输特征参数值.IMPS/IMVS理论模型拟合实验测量数据的结果表明:在不同入射光强下,随着颗粒尺寸的增大,电子扩散系数(Dn)增大,而电子寿命(τn)减小,电子传输时间(τd)也减小.Dn随颗粒尺寸增大而增加归因于薄膜表面积的减小,而τn减小可以通过缺陷之间的跃迁频率来解释,τd减小是由于TiO2薄膜内缺陷浓度减小而导致的.     

染料敏化纳米薄膜太阳电池实验研究

染料敏化纳米薄膜太阳电池（DSCs）的性能主要是由纳米多孔TiO２₂薄膜、染 料光敏化剂 、电解质、反电极（光阴极）等几个主要部分决定的.通过优化DSCs各项关键技术和材料的 性能，并通过小面积DSCs的系列实验和优化组合实验来检测各项参数对DSCs性能的影响，获 得在光照1个太阳（AM15）下，光电转换效率达到895%.这为进行产业化制备大面积DSCs 打下了良好基础. 关键词： 染料敏化 太阳电池 优化 效率     

染料敏化太阳电池内部光路折转对电子传输特性的影响

基于染料敏化太阳电池(DSC)光阳极的反射层结构,建立了含有 光路折转的电子连续性方程.计算和分析了不同吸收条件和反射条件下的调制光 电流频率响应特性,研究了DSC内部光路折转对电子传输特性的影响.通过不同膜 厚的强度调制光电流谱 测试表明, 建立的模型反映了DSC内部光路折转时调制光电流频率 响应.动力学研究结果表明, 在含有反射层的DSC中,电子传输动力学过程依赖 于光吸收系数、薄膜厚度以及大颗粒反射能力等因素. DSC内部光路折转导 致较深陷阱被电子填充,缩短了电子在陷阱中的停留时间, 减小了俘获/脱俘影响, 使电子传输过程加快.     

电极表面改性对染料敏化太阳电池性能影响的机理研究

采用强度调制光电流谱(IMPS)和强度调制光电压谱(IMVS)技术,从染料敏化太阳电池(DSC)电子传输和复合角度对比了不同光强下导电玻璃表面阻挡层及TiO₂薄膜优化使电池性能改善的内在原因.阻挡层的引入和TiO₂薄膜的优化均通过电沉积法实现.结果表明,对多孔薄膜电极的不同改性均提高了电池的短路电流J_sc和效率η,但对电子传输和复合过程的作用机理有所不同:前者延长了电子寿命τ _n,但电子传输时间τ _d变化不明显;而后者则主要是延长τ _n的同时也缩短了τ _d. 关键词： 染料敏化 太阳电池 调制光电流谱/调制光电压谱 电子输运     

大面积染料敏化太阳电池的实验研究

通过对大面积染料敏化太阳电池的实验研究，探讨了串联电阻对大面积染料敏化太阳电池光伏特性的影响问题，给出了解决这一问题的有效方法. 在此基础上制作的大面积条状电池(0.8cm×18cm)光电转换效率达到6.89%，而由此条状电池并联组成的大面积电池(15cm×20cm)的效率接近6%. 使得大面积染料敏化太阳电池的研究工作取得突破性进展，迈出了实用化的关键一步，为其工业化生产及商业化应用提供了理论和实验依据. 关键词： 大面积 染料敏化 太阳电池 串联电阻     

负偏压作用下染料敏化太阳电池界面及光电性能研究

太阳电池组件由于局部电压不匹配,其中部分电池可能较长时间工作在负偏压状态下,从而影响电池光电性能.借助拉曼光谱、电化学阻抗谱和入射单色光量子效率(IPCE)等测试手段,研究长期负偏压作用下染料敏化太阳电池光电性能的变化及其影响机理.拉曼光谱研究结果表明:电池在1000 h负偏压作用下,电解质中阳离子(Li⁺)会向光阳极(TiO₂电极)移动并嵌入TiO₂薄膜中;长期负偏压作用还会致使TiO₂/电解质界面阻抗增大和IPCE下降,导致电池开路电压升高和短路电流减小.通过加入苯并咪唑(BI)添加剂,经1000 h负偏压后电池的拉曼光谱实验表明,BI能在一定程度阻碍Li⁺的嵌入,电池具有较好的长期稳定性.不同负偏压下的老化实验进一步表明,通过加入添加剂能够使电池在长期负偏压下保持较好的稳定性. 关键词： 染料敏化 太阳电池 组件 负偏压     

电极修饰层PEO/LiF对聚合物发光二极管发光性能的提高

在以聚合物发光材料poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene)(MEH-PPV)为发光层的聚合物发光二极管(PLEDs)的金属阴极与聚合物发光层之间插入一层绝缘的聚合物poly(ethylene oxide)(PEO),发光器件的发光性能有所提高,尤其是PEO/LiF共同对Al电极修饰时发光器件的开启电压、发光强度、电流效率等性能显著提高。初步分析表明修饰层的插入造成了发光聚合物层与金属电极界面形成势垒,通过空穴堆积抑制空穴的注入,增加电子的注入,并且PEO层可以有效抑制激子在阴极的猝灭。     

Effects of compositions on properties of PEO–KI–I2 salts polymer electrolytes for DSSC

The effects of compositions on properties of PEO/KI/I₂ salts polymer electrolytes were investigated to optimize the photovoltaic performance of solid state DSSCs. XRD pattern for the mole ratio 12:1 of [EO:KI] was showed the formation of complete amorphous complex. DSC results also confirmed the amorphous nature of the polymer electrolyte. The highest value of ionic conductivity is 8.36 × 10^− 5 S/cm at 303 K (ambient temperature) and 2.32 × 10^− 4 S/cm at 333 K (moderate temperature) for the mole ratio 12:1 of EO:KI complex. The effect of contribution of [I⁻] and [I₃⁻] concentration with conductivity were also evaluated. FTIR spectrum reveals that the alkali metal cations were co-ordinated to ether oxygen of PEO. The formation of polyiodide ions, such as symmetric I₃⁻ (114 cm^− 1) and I₅⁻ (145 cm^− 1) caused by the addition of iodine was confirmed by FT Raman spectroscopic measurements. The optimum composition of PEO–KI–I₂ polymer electrolyte system for higher conductivity at ambient and moderate temperatures was reported. A linear Arrhenius type behaviour was observed for all the PEO–KI polymer complexes. Transport number measurements were carried out for several polymer electrolyte compositions. Dye-sensitized solar cells were fabricated by using higher conductivity polymer electrolyte compositions and its photoelectrochemical performance was investigated. The fill factor, short-circuit current, photovoltage and energy conversion efficiency of the DSSC assembled with optimized electrolyte composition were calculated to be 0.563, 6.124 mA/cm², 593 mV and 2.044% respectively.     

Infrared and conductivity studies on blends of PMMA/PEO based polymer electrolytes

Poly(methylmetacrylate)/poly(ethylene oxide) (PMMA/PEO) based polymer electrolytes were synthesized using the solution cast technique. Four systems of PMMA/PEO blends based polymer electrolytes films were investigated:

1. PMMA/PEO system,
2. PMMA/PEO + ethylene carbonate (EC) system,
3. PMMA/PEO + lithium hexafluorophosphate (LiPF₆) system and
4. PMMA/PEO + EC + LiPF₆ system.

The polymer electrolytes films were characterized by Impedance Spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The FTIR spectra show the complexation occurring between the polymers, plasticizer and lithium salt. The FTIR results give further insight in the conductivity enhancement of PMMA/PEO blends based polymer electrolytes.     

The Effects of Morphological Properties of Henequen Fiber Irradiated by EB on the Mechanical and Thermal Properties of Henequen Fiber/PP Composites

The aim of this study was to investigate the effects of electron beam (EB) irradiation on the morphological properties, crystallinity and surface area of henequen fiber and on the mechanical and thermal properties of henequen fiber reinforced polypropylene (PP) composites. The structure of henequen fiber was characterized by X-ray diffraction, mercury porosimetry and BET surface area analysis. The EB irradiation of 10 kGy led to the increasing of crystalline and surface pore area of henequen fiber, which contributed to the number of interlocking places with PP. From the results of tensile and impact strength tests, the highest value was observed for the composite reinforced with the henequen fiber treated with EB dose of 10 kGy, decreasing overall as EB dose increased. This tendency was also shown by coefficient of thermal expansion (CTE) measurements, but the value of CTE decreased until 50 kGy, meaning that a large total surface area can provide many interlocking places and so improve adhesion between fiber and matrix. Therefore, it can be concluded that the optimum pore surface area by 10 kGy irradiation contributes to successful mechanical interlocking between fiber and matrix and consequently enhances the mechanical and thermal properties of the composites.     

Conductivity studies on chitosan/PEO blends with LiTFSI salt

Chitosan/PEO-LiTFSI films have been prepared by the solution cast technique. The highest conductivity at room temperature was 1.4 × 10⁻⁶ Scm⁻¹ and the activation energy was 0.47 eV for chitosan/PEO blends containing 30 wt.% LiTFSI salts. The conductivity of the samples is dependent on the number of mobile ions. Paper presented at the International Conference on Functional Materials and Devices 2005, Kuala Lumpur, Malaysia, June 6 – 8, 2005.     

Interfacial morphology and friction properties of thin PEO and PEO/PAA blend films

The scanning force microscope (SFM) was used to investigate morphology of poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA) blend. The effect of solvent and dewetting in surface structure of PEO film was reported. The results manifested that the crystallization of PEO could be suppressed completely in ultrathin region via using chloroform as a solvent, and the branched-like crystallization was recovered after dewetting. Also, the effect of thickness, the ratio of PEO/PAA and dewetting in surface morphology of PEO-PAA blend films were investigated. These results showed that the crystallization was highly dependent on the ratio of PEO/PAA and the thickness of blend film. Furthermore, we assembled the PEO/PAA layer-by-layer film by spin-casting method for the first time, which exhibited highly efficiency. As a complementary tool, we also used lateral force microscopy (LFM) to explore surface information of these films. The result was indicative of interfacial constraints in ultrathin region, and also was supported by the results showing the spin-casting PEO/PAA blends rather than heterogeneous mixture.     

新型多孔凝胶电解质的制备及其在准固态柔性基染料敏化太阳电池中的应用

制备了一种新型多孔聚丙烯酸/十六烷基三甲基溴化铵聚吡咯凝胶电解质,并将其应用于柔性基染料敏化太阳电池(DSSC)。通过扫描电镜表征、热重分析测试、电化学性能测试和柔性电池光电性能测试等手段,分析了凝胶电解质对柔性基DSSC的光电性能影响。研究结果表明:随着聚吡咯的引入,提高凝胶电解质导电性以及催化电解质中的I-/I3-离子电对等性能,最终在100mW/cm2[大气质量(AM)1.5]光照条件下,测得基于该准固态凝胶电解质的柔性基DSSC光电转换效率达1.28%。     

PVDF–PEO/ZSM-5 based composite microporous polymer electrolyte with novel pore configuration and ionic conductivity

A novel composite microporous polymer electrolyte based on poly(vinylidene fluoride), poly(ethylene oxide), and microporous molecular sieves ZSM-5 (denoted as PVDF–PEO/ZSM-5) was prepared by a simple phase inversion technique. PEO can obviously improve the pore configuration, such as pore size, porosity, and pore connectivity of PVDF-based microporous membranes, results in a high room temperature ionic conductivity. Microporous molecular sieves ZSM-5 can further improve the mechanical strength of PVDF–PEO blends and form special conducting pathway in PVDF–PEO matrix by absorb liquid electrolyte in its two-dimensional interconnect channels. The high room temperature ionic conductivity combined with good mechanical strength implies that PVDF–PEO/ZSM-5 based composite microporous polymer electrolyte can be used as candidate electrolyte and/or separator material for high-performance rechargeable lithium batteries.     

Dielectric spectra of LiTFSI-doped chitosan/PEO blends

Solid-polymer-blend electrolyte consisting of chitosan and polyethylene oxide (PEO) in a 1:1 weight ratio and doped with lithium trifluoromethanesulfonimide (LiTFSI) salt was prepared by solution cast technique. The highest conducting film with conductivity value of 1.40 × 10^-6 S cm⁻¹ at room temperature consists of 30 wt% LiTFSI. The temperature dependence for the highest conducting film obeyed Arrhenius relationship. From loss tangent–frequency plots at different temperatures, the frequency f _max at which the plot is a maximum was obtained. From this, ln f _max vs 10³/T was plotted. The activation energy value obtained from the log σ vs 10³/T plot and ln f _max vs 10³/T plot is about the same, suggesting that the processes of conductivity and relaxation for the charge carriers are the same. This paper was presented at the International Conference on Solid State Science and Technology 2006, Kuala Terengganu, Malaysia, Sept. 4–6, 2006.