染料N719和Q-PbS复合敏化Zn_2TiO_4纳米晶薄膜电极的研究

为了有效的利用太阳能,提高纳米晶薄膜太阳能电池的效率,针对太阳的发射光谱和纳米薄膜的吸收光谱,设计出复合敏化的薄膜太阳能电池。采用溶胶-凝胶法在FTO玻璃上制备了Zn_2TiO_4纳米晶薄膜,用XRD和SEM分别对其物相及形貌进行了表征;以染料N719和Q-PbS为敏化剂,制备了多种Zn_2TiO_4纳米晶薄膜电极,分别测试了他们的UV-Vis吸收光谱;优选出敏化效果好的电极为光阳极组装了太阳能电池,并进行了光电性能测试。研究结果表明,纳米晶薄膜为尖晶石结构的Zn_2TiO_4,呈球形多孔,平均晶粒约80nm;染料N719和Q-PbS敏化的电极,光响应范围均扩展到可见光区,出现了明显的红移,而且复合敏化的电极在可见光区具有较强的吸收;制备了多种染料敏化太阳能电池(DSSC),在模拟太阳光下,Zn_2TiO_4+Q-PbS(2min)+N719薄膜电极组成的DSSC的性能最优,其开路电压0.65V,电流密度3.3mA/cm^2,填充因子77%和转化效率达1.61%。

美人蕉花青素/N719染料共敏化太阳能电池性能

为了拓宽染料电池对太阳光谱的响应范围,提高光电转化效率,从天然植物美人蕉中提取了天然花青素染料,作为染料电池的共敏化剂。测试了花青素乙醇溶液的紫外-可见光谱,利用循环伏安法研究了它的氧化还原行为,并测试了其与N719共同敏化后的染料敏化太阳能电池的光学性能。结果表明:美人蕉花青素符合光敏染料的电子注入驱动力的要求;与N719的最优共敏化条件是花青素敏化60 min,N719敏化24 h。共敏化后电池光电压为0.8 V,短路电流密度为5.97 mA/cm2,填充因子F为0.55。光电转换效率为2.65%,比N719单独敏化提高了61%。说明美人蕉的花青素染料作为共敏化剂使用,能够拓展对太阳光谱的吸收范围,并且有助于提高染料电池性能。

N719染料敏化BaTiO3@TiO2纳米复合电极的制备及性能研究

BaTiO3是非常常见的铁电材料,经常用于制备铁电光伏器件或与半导体器件相结合来优化光伏器件的光电性能。采用水热法合成了BaTiO3纳米颗粒,并在FTO玻璃上制备了BaTiO3纳米晶薄膜,通过TiCl4水溶液后处理的方法在BaTiO3纳米薄膜上形成不同厚度的TiO2层,利用XRD、SEM和TEM分别对BaTiO3@TiO2纳米复合薄膜的物相和形貌进行了表征。将此电极经N719染料敏化后作为染料敏化太阳能电池的光阳极,并进行了光电性能测试。研究结果表明,水热法制备的BaTiO3薄膜晶型为四方相,呈球形多孔,平均粒径约50 nm;经过TiCl4后处理,在BaTiO3薄膜表面形成了锐钛矿相的TiO2颗粒。180℃下水热合成的BaTiO3纳米颗粒经过4次TiCl4后处理制备成的染料敏化太阳能电池取得了最优性能,其光电流密度9.78 mA cm-2,开路电压765 mV,填充因子76.1%和光电转换效率5.69%。

An Effective of Dye Molecules with Cadmium Sulfide Nanorods in Dye Sensitized Solar Cell (DSSCs)

The aligned hexagonal cadmium sulfide nanorods (CdSNR) have been synthe-sized by hydrothermal technique at 200&#186C on fluorine tin oxide (FTO) sub-strates. Dye sensitized solar cells (DSSCs) based on the photoelectrode core-shell CdSNR array with conductive polymers nanocomposite of polyaniline (PANI) and poly(3,4-ethylenedioxyl-thiophene)/poly(styrene-sulfonate) (PEDOT:PSS) were fabricated and designed with different types of dye molecules. DSSCs were characterized utilizing scanning electron microscopy (SEM), Raman scattering, energy dispersive spectroscopy (EDS), UV-Vis absorption spectroscopy, X-ray diffraction (XRD), and photocurrent-voltage (J-V) characteristic. Results show that under illumination (AM 1.5 G), the high power conversion energy (PCE) was achieved for CdSNR/PANI-PEDOT:PSS device when it sensitized with ruthenium (II) (dye N-719) of 0.91% and a short circuit current density (Jsc) of 4.21 mA/cm2 in comparison with the other devices, which sensitized with natural dyes. The high performance of the CdSNR/PANI-PEDOT:PSS-N719 device attributed to the wide range of absorption and photostability for N719. This work shows that the CdSNR with N719 can be appropriate candidate for photovoltaics device for their low cost fabrication procedure and excellent absorption.

Al掺杂对TiO_2薄膜性质的影响

利用反应磁控共溅射法,在改变掺Al功率的条件下对TiO_2薄膜进行掺杂;研究了Al掺杂对TiO_2薄膜的表面形貌、晶体结构和禁带宽度的影响,发现Al掺杂后,薄膜晶体结构、禁带宽度均发生变化;并将纯态和掺Al的TiO_2薄膜浸入N719染料进行敏化,发现晶体结构的变化对TiO_2薄膜吸附N719染料分子的效率产生重要影响。

Multispectral Plasmon of Anisotropic Core-shell Gold Nanorods@SiO2： Dual-band Absorption Enhancement with Coupling Dye Molecules

Direct evidence of effects of surface plasmon resonance（SPR） of gold naaorods（GNRs） on dual-band light absorption enhancement with coupling dye molecules was reported by introducing gold nanorod@SiO2（GNR@SiO2） core-shell nanoparticles into a photoelectric conversion system. GNR with asymmetric shape had unusual anisotropic SPR[transversal surface plasmon resonance（TSPR） and longitudinal surface plasmon resonance（LSPR）]. The excel- lent SPR of GNR made it a promising candidate as enhancing light absorption material to increase power conversion efflciency（PCE）. The PCE was improved nearly 17.2% upon incorporating GNRs, mostly due to the increase in Jsc, while Vo~ and FF were unchanged. The improvement was mostly contributed by the SPR of the GNRs with coupling of N719. And there was also a complementary to N719 in visible light range. Therefore, SPR is an effective tool in improving the photocurrent and consequently enhancement of PCE. The TSPR and LSPR effects of GNRs on light harvesting were reflected in the increased monochromatic incident photon-to-electron conversion efficiency（IPCE）. We also utilized finite-difference tirne-domain（FDTD） to investigate the light coupling of GNRs with TiO2. Compare to the base anode, the IPCE of optimized electrode showed significant improvement and peaks broadening at 500--600 nm and 610--710 nm. We got an increase in overall conversion efficiency from 6.4% to 7.5%.

The effect of modified layers on the performance of inverted ZnO nanorods/MEH-PPV solar cells

We fabricate inverted organic/inorganic hybrid solar cells based on vertically oriented ZnO nanorods and polymer MEH-PPV. The morphology of ZnO nanorods and ZnO nanorods/MEH-PPV hybrid structure is depicted by using scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscope (AFM), respectively. It is observed that ZnO nanorods array grows primarily aligned along the perpendicular direction of the ITO substrate. The MEH-PPV molecule does not enter the interspace between ZnO nanorods completely according to SEM picture. It results in the small and bad contact area between ZnO nanorods and MEH-PPV. To improve the photovoltaic performance, we also fabricate another kind of photovoltaic (PV) device modified by N719 dye, and exploit the effect of N719. After the modification of ZnO nanorods by N719, not only Jsc increases from 0.257 mA/cm2 to 0.42 mA/cm2, but also Voc enhances from 0.37 V to 0.42 V. Insert LiF buffer layer between MEH-PPV and anode, Jsc of 1.05 mA/cm2 is obtained, and it is 2.5 times that the device without LiF.