一步水热法制备TiO2复合结构及光伏性能

采用一步水热法制备TiO2纳米棒阵列,研究了无水乙醇作为前驱物替换去离子水对纳米棒阵列的形貌的影响。实验发现,当无水乙醇的含量达到100%的时候,在生长的TiO2纳米棒阵列的上面获得一层以TiO2纳米棒为基本单元的微米球,从而制备出TiO2复合纳米阵列薄膜。通过XRD和TEM发现,样品为单晶四方金红石结构TiO2构成的阵列薄膜,将样品组装成染料敏化太阳能电池后,电池的开路电压和短路电流分别为Voc=0.63 V,Jsc=10.9 mA·cm-2,填充因子FF=56.3%,转换效率达到η=4.1%。     

TiO2纳米微球的制备及在染料敏化太阳能电池中的应用

以四氯化钛、盐酸为原料,制备出花状TiO_2纳米微球,利用扫描电子显微镜(SEM)、X射线衍射(XRD)等测试方法,对样品的结构和形貌进行了表征。为了提高TiO_2微球电池的光电性能,利用TiO_2微球作为反射层构造了双层结构的薄膜电极,结果表明,双层结构染料敏化太阳能电池在100 m W·cm-2(1.5 G)光照条件下,短路光电流Jsc=17.64 m A·cm-2,开路光电压Voc=0.74 V,填充因子FF=0.63和光电转化效率η=8.33%。相比TiO_2微球制备的太阳能电池,双层结构染料敏化太阳能电池光电转化效率提高至5.3倍。最后对电极中染料的吸附量、电极的光散射性能和电池的电化学阻抗做了进一步研究和分析,研究表明,双层结构电池增强光的捕获能力,从而提高光伏性能。     

基于不同取代基的噻吩-三苯胺染料敏化剂的合成与光伏性能

本文合成了含3种不同取代基的噻吩-三苯胺染料敏化剂(H1,H2和H3),并将其应用于二氧化钛纳米晶染料敏化太阳能电池.系统地研究了3种染料的光物理、电化学和光伏性能.基于H1的染料敏化太阳能电池获得了9.10%的光电转换效率(Voc=0.72V,Jsc=18.03mAcm-2,FF=0.70).     

TiO2纳米片/巢状分级结构纳米阵列薄膜的制备及其在染料敏化太阳能电池中的应用

采用水热合成法在氟掺杂二氧化锡(FTO)导电玻璃基底上得到TiO2纳米阵列薄膜,并进一步通过NaOH溶液水热处理制备了由巢状纳米阵列及纳米片覆盖层构成的TiO2纳米阵列分级结构一体化薄膜.采用场发射扫描电镜(FE-SEM),X射线衍射(XRD),紫外-可见(UV-Vis)漫反射光谱和吸收光谱技术对TiO2薄膜的结构和性质进行表征.FE-SEM结果表明:分级结构TiO2薄膜膜厚为1.5μm,薄膜由一层纳米片覆盖层(约0.2μm高)和一层巢状纳米阵列层(约1.3μm高)组成.XRD谱图表明TiO2薄膜为锐钛矿相.UV-Vis光谱显示分级结构TiO2薄膜具有较强的光捕获能力和染料吸附能力.TiO2纳米片/巢状分级结构纳米阵列薄膜作为光阳极,可有效地提高染料敏化太阳能电池的光电转换效率,其短路电流(Jsc)为7.79mA·cm-2,开路电压(Voc)为0.80V,填充因子(FF)为0.40,光电转换效率(η)为2.48%,其光电转换效率较TiO2纳米阵列薄膜提高了近10倍.     

N,N-二苯基取代的芳炔化合物的合成及光伏性能

以简单原料出发,通过Sonogashira偶联反应和三甲基硅基(TMS)的保护与脱保护,合成了一系列N,N-二苯基取代的芳炔化合物SC1～SC5.这类化合物是以N,N-二苯基为电子给体,羧基为电子受体,芳香炔体系为共轭桥的染料.将化合物SC5吸附到TiO2膜上制备成有机染料敏化太阳能电池,在AM 1.5,100 mW/cm2的模拟太阳光下,电池的光电转换效率(IPCE)值最大达到64%,而且在350～580 nm的范围内都可达到50%以上.电池的短路电流密度Jsc=8.0mW/cm2,开路电压Voc=0.75 V,填充因子为FF=0.70,总光电转换效率η=4.2%.     

水相一步合成锐钛矿型二氧化钛空心球

报道了水相一步直接合成晶体TiO2空心球的方法. 以水溶性的过氧化钛配合物(peroxo-titanium complex, PTC)为前驱体、聚苯乙烯(polystyrene, PS)球为模板, 在水溶液体系中可直接制备得到锐钛矿型纳米TiO2空心球. 与传统的模板法相比, 模板的包覆、去除及TiO2壳层的晶化等步骤在水相中可一步完成. 利用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)及热重分析仪(TGA)对所合成的纳米TiO2空心球进行了表征, 同时推断了可能的反应机理.     

二氧化钛多孔纳米片在染料敏化太阳电池中的应用（英文）

运用连续吸附反应法和化学腐蚀-沉积法,用ZnO/FTO(氟掺杂氧化锡)多孔纳米片为模板,制备了TiO2/FTO多孔纳米片。研究了吸附次数对形貌、光散射性能和染料敏化太阳电池性能的影响。最佳吸附次数为30,由此得到的太阳能电池的效率、短路电流密度Jsc、开路电压Voc和填充因子FF分别为:5.57%、9.26 mA·cm-2、0.835 V和72.04%。这个效率略高于P25(5.32%),但远高于ZnO(2.41%)。     

二氧化钛多孔纳米片在染料敏化太阳电池中的应用

运用连续吸附反应法和化学腐蚀-沉积法,用ZnO/FTO(氟掺杂氧化锡)多孔纳米片为模板,制备了TiO2/FTO多孔纳米片。研究了吸附次数对形貌、光散射性能和染料敏化太阳电池性能的影响。最佳吸附次数为30,由此得到的太阳能电池的效率、短路电流密度Jsc、开路电压Voc和填充因子FF分别为:5.57%、9.26 mA·cm-2、0.835 V和72.04%。这个效率略高于P25(5.32%),但远高于ZnO(2.41%)。     

负偏压下（Ni-Mo）/TiO2膜电极光电催化降解罗丹明B的性能和机理

用复合电沉积方法制备了(Ni-Mo)/TiO2薄膜电极,以扫描电子显微镜(SEM)、X射线衍射(XRD)、拉曼光谱(Raman Spectra)和紫外-可见漫反射光谱(DRS)对薄膜的表面形貌、晶相结构和光谱特性进行了表征,在负偏压和可见光作用下,以罗丹明B为模拟污染物研究了薄膜的光电催化性能.采用电化学技术和向溶液中加入活性物种捕获剂的方法对薄膜光电催化降解机理进行了探索.结果表明:(Ni-Mo)/TiO2薄膜是由粒径为50～100 nm的TiO2纳米粒子相和纳米晶Ni-Mo固溶体相构成的复合薄膜.薄膜具有较高的光电催化活性,在-0.4 V偏压和可见光照射下反应60 min,复合薄膜光电催化罗丹明B(c=5 mg/L)的降解率是多孔TiO2(P25)/ITO纳米薄膜的1.56倍.复合薄膜电极中Ni-Mo纳米晶合金对溶解氧和激发电子还原反应的催化作用是光电催化降解活性提高的重要原因.通过调节外加偏压,可以控制电极溶液界面间染料与活性氧化物种的存在形式及其相互作用,是研究可见光催化降解反应历程的有效方法.在负偏压和可见光作用下,羟基自由基和染料正离子自由基对染料的光电催化降解有决定性作用.     

TiO_2纳米棒和CdSe纳米棒复合膜与聚3-甲基噻吩杂化太阳能电池研究

采用水热法制备了TiO2和CdSe两种纳米棒材料,将两种纳米材料制备成TiO2/CdSe复合纳米棒膜电极,并在复合膜上电化学聚合生成聚3-甲基噻吩poly(3-methylthiophene)(PMeT),研究了其光电化学性能.实验表明,当TiO2与CdSe的物质的量复合比为2:1,PMeT的聚合时间为40s,在电极电势为-0.2V下ITO/TiO2/CdSe/PMeT电极光电转换效率(IPCE)达到56%,对比ITO/TiO2/CdSe复合膜电极在长波方向的光电转换效率明显提高,光吸收截止波长发生了明显的红移.同时以ITO/TiO2/CdSe/PMeT组装了简易的杂化太阳电池,初步研究了光电池性能,光电池总效率为0.08%,Voc=0.4V,jsc=0.61mA/cm2,ff=0.33.     

Efficient eosin y dye-sensitized solar cell containing Br-/Br3- electrolyte

We found that Br-/Br3- is more suitable than an I-/I3- couple in dye-sensitized solar cells in terms of higher open-circuit photovoltage (Voc) production and higher overall energy conversion efficiency (eta) if the dye sensitizer has a more positive potential than that of Br-/Br3-. Under simulated AM1.5 one sun, an eosin Y dye-sensitized solar cell containing 0.4 M LiBr + 0.04 M Br2 electrolyte in acetonitrile yielded a short-circuit photocurrent (Jsc) of 4.63 mA cm(-2), Voc of 0.813 V, and fill factor (FF) of 0.693, corresponding to 2.61% of eta. Under the same conditions except for the electrolyte 0.4 M LiI + 0.04 M I2 in acetonitrile instead, the device produced 1.67% of eta (Jsc = 5.15 mA cm(-2), Voc = 0.451 V, FF = 0.721). Replacement of I-/I3- with Br-/Br3- in eosin Y dye-sensitized solar cells yielded a significant increase in Voc offset by slight decreases in Jsc and FF, leading to an increase in eta by 56%. The significant gain in Voc was attributed to the enlarged energy level difference between the redox potential of the electrolyte and the Fermi level of TiO2 and the suppressed charge recombination as well. The rate for charge recombination between bromine and the injected electrons was determined to be first order in bromine.     

Alkyl-functionalized organic dyes for efficient molecular photovoltaics

We designed and synthesized new alkyl-functionalized organic dyes, MK-1 and MK-2, for dye-sensitized solar cells (DSSCs). Based on the MK-2 dye, a high performance of efficiency (eta, 7.7%; short-circuit current density Jsc = 14.0 mA cm-2, open-circuit voltage Voc = 0.74 V, and fill factor FF = 0.74) was achieved under AM 1.5 G irradiation (100 mW cm-2). Remarkably, the relatively higher Voc for DSSCs based on MK-1 and MK-2 dyes, which have long alkyl chains, were observed among the organic dyes caused by the increasing of the electron lifetime in the conduction band of TiO2. Our molecular design of alkyl-functionalized dyes strongly suggests the promising performance of molecular photovoltaics based on organic dyes.     

Novel polyene dyes for highly efficient dye-sensitized solar cells

We have developed an efficient and novel polyene-dye-sensitized nanocrystalline TiO2 solar cells producing a 6.8% solar energy-to-electricity conversion efficiency (eta) under AM 1.5 irradiation (100 mW cm(-2)): short-circuit current density (Jsc), 12.9 mA cm(-2), open-circuit photovoltage (Voc), 0.71 V, fill factor (ff), 0.74.     

水热法可控合成二氧化钛纳米晶及其在染料敏化太阳能电池中的应用

本文报道了水热法可控合成二氧化钛纳米晶及其在染料敏化太阳能电池中的应用.选择合适的有机碱胶化剂,能很好地控制二氧化钛纳米晶的生长,形成不同形貌和粒径的锐钛矿型二氧化钛纳米晶颗粒.染料敏化太阳能电池光电性能测试结果表明,以四乙基氢氧化铵为胶化剂合成的边长为8～13nm的正方形二氧化钛纳米晶构成的光阳极光电性能优于以四丁基氢氧化铵为胶化剂合成的边长为7～10nm的正方形二氧化钛纳米晶以及长18～35nm,宽10～18nm的长方形二氧化钛纳米晶构成的光阳极.用较高浓度的四甲基氢氧化铵胶化剂能合成球形或椭球形亚微米级二氧化钛颗粒,以其为散射中心在光阳极中构建散射层,染料敏化太阳能电池的光电转换效率能由6.77%提高到8.18%.     

含Ullazine结构基元的共轭聚合物的合成及其光电性能研究

将Ullazine结构基元引入到聚合物主链或侧链中,分别与吡咯并吡咯二酮(DPP)、2,5-双(三甲基锡)噻吩共聚得到了二元共聚物PB和三元共聚物PT,分别利用凝胶渗透色谱和热重分析表征了聚合物的分子量和热稳定性,并研究了聚合物的光物理、电化学和光伏性能.基于共聚物PB和PT作为电子给体材料的聚合物太阳能电池器件测试结果表明,二元共聚物PB由于具有较低的能级水平从而获得较高开路电压,而侧链含Ullazine结构基元的三元共聚物PT具有更宽的吸收光谱和更高的空穴迁移率,获得了更高的短路电流和能量转换效率.     

Structural tuning of low band gap intermolecular push/pull side-chain polymers for organic photovoltaic applications

A series of novel low band gap donor-acceptor (D-A) type organic co-polymers (BT-F-TPA,BT-CZ-TPA and BT-SI-TPA) consisting of electron-deficient acceptor blocks both in main chains (M1) and at the pendant (M2) were polymerized with different electron rich donor (M3-M5) blocks,i.e.,9,9-dihexyl-9H-fluorene,N-alkyl-2,7-carbazole,and 2,6-dithinosilole,respectively,via Suzuki method.These polymers exhibited relatively low band gaps (1.65-1.88 eV) and broad absorption ranges (680-740 nm).Bulk heterojunction (BHJ) solar cells incorporating these polymers as electron donors,blended with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) or [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as electron-acceptors in different weight ratios were fabricated and tested under 100 mW/cm2 of AM 1.5 with white-light illumination.The photovoltaic device containing donor BT-SI-TPA and acceptor PC71BM in 1:2 weight ratio showed the best power conversion efficiency (PCE) value of 1.88％,with open circuit voltage (Voc) =0.75 V,short circuit current density (Jsc) =7.60 mA/cm2,and fill factor (FF) =33.0％.     

中空TiO_2微球的制备及对聚丙烯酸酯薄膜性能的影响

采用阳离子聚苯乙烯微球作为模板,钛酸四丁酯为钛源,氨水为催化剂,制备了中空TiO_2微球.采用X射线衍射、扫描电镜及比表面测定仪对其形貌和结构进行了表征,并考察了模板粒径、钛源用量以及催化剂用量对中空TiO_2微球形貌的影响.通过物理共混法将其引入至聚丙烯酸酯乳液中并成膜,研究了复合薄膜的保温性能、抗紫外性能及力学性能.结果表明,锐钛矿相中空TiO_2微球模板粒径、钛源用量以及催化剂用量影响中空TiO_2微球的空心尺寸、壁厚及壳层致密性.中空TiO_2微球可显著提升聚丙烯酸酯薄膜的保温性能、抗紫外性能和力学性能.采用不同粒径的模板制备的中空TiO_2微球对复合薄膜的各项性能均有影响,其中模板粒径为140 nm时复合薄膜性能最优,光反射率提升63%,导热系数降低27%,且在波长小于360 nm范围内,紫外透过率几乎为0,抗张强度增加100%,断裂伸长率提升62%.     

Oligothiophene-containing coumarin dyes for efficient dye-sensitized solar cells

We have developed oligothiophene-containing coumarin dyes fully functionalized for dye-sensitized nanocrystalline TiO(2) solar cells (DSSCs). DSSCs based on the dyes gave good performance in terms of incident photon-to-current conversion efficiency (IPCE) in the range of 400-800 nm. A solar energy-to-electricity conversion efficiency (eta) of 7.4% was obtained with a DSSC based on 2-cyano-3-[5'-(1,1,6,6-tetramethyl-10-oxo-2,3,5,6-tetrahydro-1H,4H,10H-11-oxa-3a-aza-benzo[de]anthracen-9-yl)-[2,2']bithiophenyl-5-yl]acrylic acid (NKX-2677) under simulated AM 1.5G irradiation (100 mW cm(-2)) with a mask: short-circuit current density (J(sc)) = 13.5 mA cm(-2); open-circuit voltage (V(oc)) = 0.71 V; fill factor (FF) = 0.77. Transient absorption spectroscopy measurements indicated that electron injection from NKX-2677 to the conduction band of TiO(2) is very rapid (<100 fs), which is much faster than the emission lifetime of the dye (1.0 ns), giving a highly efficient electron injection yield of near unity.