P3HT及CTCHT修饰纳米TiO2的光电性能研究

用光电流作用谱、光电流-电势图等光电化学方法研究了聚3-己基噻吩(P3HT)及3-己基噻吩和2-噻吩甲酸共聚物(CTCHT)修饰纳米结构TiO2电极的光电转换性质。结果表明,经修饰后的纳米TiO2电极光电流明显增强,光电转换效率得到明显提高。在复合膜电极中存在p-n异质结,异质结的存在有利于光生电子-空穴对的分离,降低了电荷的反向复合几率,提高了光电转换效率。     

巯基化P3HT衍生物的合成与表征

用GRIM(Grignard Metathesis Method)合成了聚(3-溴己基噻吩),并在硫代乙酸钾和氢化铝锂的作用下合成了巯基化的P3HT衍生物聚(3-(6-巯基己基)噻吩)。通过红外光谱、核磁共振波谱、凝胶渗透色谱、紫外-可见光谱、荧光光谱以及电化学分析对中间产物和最终产物的结构和光电性能进行了表征。结果表明,所合成聚合物与目标产物的结构一致,聚合物的数均相对分子质量为5621,多分散系数为1.39,在氯仿溶液中最大吸收波长为408 nm,最大发射波长为545 nm,电化学能隙为1.81 eV。     

纳米结构TiO2/聚3-甲基噻吩多孔膜电极光电化学研究

用光电流作用谱、光电流-电势图等光电化学方法研究了ITO/聚3-甲基噻吩(PMeT)膜电极和ITO/TiO2/PMET复合膜电极的光电转换性质.结果表明,PMET膜导带位置为-3.44eV,禁带宽度为1.93eV.修饰ITO/TiO2电极可使光电流发生明显的红移,从而提高了宽禁带半导体的光电转换效率.     

水热法合成CdSe/P3HT复合纳米晶

以1-十八烯(ODE)为反应介质,硬脂酸镉和硒粉分别为镉源和硒源,聚(3-己基噻吩-2,5-二基)(P3HT)为模板,在无三丁基膦或三辛基膦参与的条件下,采用水热法在较低温度下原位合成了硒化镉/聚(3-己基噻吩-2,5-二基)(CdSe/P3HT)复合纳米晶。并对CdSe/P3HT复合纳米晶的结构、形貌和性能进行了表征。研究结果表明:制得的CdSe/P3HT复合纳米晶平均粒径5.27nm,分布均匀,排列整齐,晶面间距为0.350nm,荧光淬灭强度为38.7%,用于光电材料可提高光电转化效率。     

基于咔唑供体的敏化染料的合成及其光电性质

以咔唑为供体,设计并合成了具有D-A-π-A或D-π-A结构的有机敏化染料2-氰基-3-{5-[7-(9-己基咔唑-3-基)-苯并[1,2,5]噻二唑-4-基]-2-噻吩基}-丙烯酸(CVBTC)和2-氰基-3-{5-[7-(9-己基咔唑-3-基)]-2-噻吩基}-丙烯酸(CVHTC)。研究了结构变化对敏化染料的光物理性质、电化学性质和光伏性能的影响。研究表明,在染料CVHTC的D-π-A结构链上插入受体苯并噻二唑单元,得到的具有D-A-π-A结构的染料CVBTC的共轭体系变大,带隙变小,光吸收性能得到明显提升。CVBTC和CVHTC的HOMO能级分别为-5.24和-5.52eV,LUMO能级分别为-3.20和-2.88eV,均能与常见电解质I~-/I_3~-(-4.60eV vs vacuum)以及TiO_2导带能级(-4.40eV vs vacuum)相匹配,都可用作DSSCs的敏化染料。并且与CVHTC相比,具有D-A-π-A结构CVBTC,因苯并噻二唑单元的引入,其光电池的短路电流和光电转换效率均得到明显提升。     

共轭链含偶氮苯聚噻吩衍生物的合成及光电性能

以对乙酰胺基苯胺为原料合成4,4′-二氨基偶氮苯,进一步经重氮化、Sandmeyer反应得到4,4′-二溴偶氮苯,再经Suzuki偶联反应得到4,4′-二(2-噻吩基)偶氮苯,利用红外光谱(IR)和核磁共振谱对各产物进行了表征。采用FeCl3氧化聚合成得到聚4,4′-二(2-噻吩基)偶氮苯,并测定其UV-Vis吸收光谱、溶液及固体荧光光谱、循环伏安曲线及光致发光光谱,得到该聚合物光学带隙Eg为2.14eV,电化学带隙为2.06 eV,EHOMO为-5.56 eV,ELUMO为-3.50 eV。     

P3HT和MEH-PPV薄膜的光谱性质和结晶研究

溶剂不同会影响聚合物的光敏形貌和一些其他性能,本文就常用的几种溶剂(氯仿、四氢呋喃、二硫化碳、甲苯)对聚3-己基噻吩(P3HT)和聚[2-甲氧基-5(2'-乙基己氧基)对苯乙炔](MEH-PPV)的光谱性质和结晶过程的影响进行初步的研究.     

新型窄带隙聚合物太阳能电池材料的合成及性能研究

为了寻找更优异的太阳能电池材料,通过stille偶联反应以2,2′-联噻吩作为给体单元,以4,7-二(3-己基噻吩-2-基)-5,6-二氟-[2,1,3]苯并噻二唑作为受体单元,合成了一种新型聚合物。通过引入支链和氟原子提高了聚合物的性质。利用傅里叶变换红外光谱仪和核磁共振氢谱仪表征了聚合物的结构,采用热重差热综合热分析仪表征了聚合物的热稳定性,并通过紫外-可见吸收光谱和循环伏安法研究了其光电性能。结果表明,聚合物的热分解温度为366℃,带隙为2.16eV,理论开路电压为1.02V,在聚合物太阳能电池的制备中可将其作为给体材料。     

聚(3-己基噻吩)的合成与表征

采用化学氧化法,用三氯化铁(FeCl3)作氧化剂合成了聚3-己基噻吩(P3HT)。研究了反应时间、氧化剂和单体摩尔比对转化率的影响,结果表明转化率随反应时间延长而增加,氧化剂和单体摩尔比为3∶1时转化率最高,达到71%。用红外光谱,紫外-可见光谱和核磁共振(1H-NMR)表征了P3HT的结构。紫外-可见光谱表明P3HT溶液禁带宽度约为1.91eV,根据1H-NMR计算P3HT结构规整度约为80%。研究了反应时间对P3HT分子量的影响,发现随聚合反应时间延长,分子量先迅速增加然后逐渐减小。     

聚合物光伏电池材料真空极化取向的研究

聚[2-甲氧基5-(2′-乙基己氧基)对苯乙炔](MEH-PPV)和聚3-己基噻吩(P3HT)是典型的共轭聚合物,可以作为新型的光伏电池材料。真空条件下对两种聚合物材料进行极化取向实验,可以增加载流子的迁移能力,提高导电能力,有利于聚合物太阳能薄膜电池性能的改善。     

Electrical stability of polyimide siloxane films for interlayer dielectrics in multilevel interconnections

Electrical stability of a polyimide siloxane (PSI) film for ultra-large scale integrated circuit (ULSI) multilevel interconnections is studied. The PSI films, modified by p-aminophenyltrimethoxysilane (APTMS), are designed to have three-dimensional polymer structures through Si–O bonds. It has been revealed that the PSI films are more stable in electrical properties at higher temperatures than 150°C, as compared to the conventional polyimide (PI) films. The electrical conduction mechanism study for the PSI films has revealed that Schottky emission is dominant. Barrier height φ_B obtained from the electrical property for the PSI film was 0.460 eV in the temperatures ranging from 25–250°C. On the other hand, barrier height of 0.422 eV at lower temperatures than 150°C and activation energy of 1.09 eV at higher temperatures than 150°C were obtained for the conventional PI film. The difference in polymer structure is very sensitive to the electrical conduction at high temperature, due to sodium ion migration. The ideal band diagrams of metal-insulator-semiconductor (MIS) structures were also discussed. The optical band gaps for PSI and conventional PI films were 3.320 eV and 3.228 eV, respectively. This result suggests that the band gap of PI films can be enlarged by modification with Si–O components. The differential barrier height between the PSI and conventional PI films is 0.038 eV, and is close to the difference in half of optical band gaps (0.046 eV).     

Grain size dependent optical band gap of CdI2 films

The thermally evaporated stoichiometric CdI₂ films show goodc-axis alignment normal to substrate plane for film thickness up to 200 nm. The optical absorption data indicate an allowed direct interband transition across a gap of 3.6 eV in confirmation with earlier band structure calculations. However, part of the absorption data near band edge can be fitted to an indirect band gap of 3 eV. The dependence of band gap on film thickness (> 200 nm) can be explained qualitatively in terms of decreasing grain boundary barrier height with grain size.     

Some physical properties of evaporated thin films of antimony trisulphide

The optical properties of thin films of red Sb₂S₃ prepared by vacuum evaporation on amorphous substrates were determined from transmission measurements. The variation of the extinction coefficient,K, shows structures at energies of 4.4 and 5.4 eV. The band gap was found to be 1.7 eV for film of thickness 56 nm, and increase with thickness. The interpretation of structure was inferred from transmission electron microscopy and X-ray diffraction for thin films of antimony trisulphide. The investigated film thicknesses were from 46 to 64 nm.     

过渡金属(Mn2+、Ni2+、Fe3+、Cu2+)掺杂ZnO基稀磁半导体的制备及性质

利用溶液腐蚀法制备了Mn2+、Ni2+、Fe3+、Cu2+离子掺杂的ZnO基稀磁半导体。XRD表明掺杂后的ZnO仍然保持单一的纤锌矿结构,没有任何杂质相产生。由紫外-可见光反射谱可知掺杂后吸收边发生了红移。掺杂前ZnO的带隙为3.20eV,对样品分别掺入Mn、Ni、Fe和Cu后的带隙分别为3.19eV、3.15eV、3.08eV和3.17eV。掺杂后样品的室温PL谱除了紫外发射峰外,对于Mn掺杂的样品还在蓝光区域出现了2个分别位于424nm和443nm的发射峰,Fe掺杂的样品出现了一个位于468nm的微弱发射峰,Cu掺杂的样品出现了位于469nm及535nm的很宽的发射峰。室温磁滞回线显示掺杂后样品有明显的铁磁性,掺入Mn、Ni、Fe和Cu样品的剩余磁化强度(Ms)分别为0.3902×10-3emu/cm3、0.454emu/cm3、0.372emu/cm3和0.962×10-3emu/cm3,矫顽力分别为47Oe、115.92Oe、99.33Oe和23Oe。经分析室温铁磁性来源于缺陷调制的Mn2+-Mn2+长程铁磁交换相互作用。     

利用Heck反应制备3-甲基噻吩与芴的嵌段共聚物及其性能

采用Heck反应合成了3-甲基噻吩齐聚物及3-甲基噻吩与芴的交替和嵌段共聚物。用凝胶渗透色谱（GPC）、核磁共振谱（1H-NMR）、紫外-可见光谱和荧光光谱对所得聚合物进行了表征。结果表明,利用Heck反应成功地制备了上述聚合物。在溶液和薄膜状态下嵌段共聚物与交替共聚物的最大紫外吸收峰分别为414 nm、394 nm和...     

Deposition and characteristics of CdO films with absolutely (200)-preferred orientation

CdO crystal thin films with (200)-preferred orientation have been prepared on Si and glass substrates by dc reactive magnetron sputtering method. At an optimum substrate temperature of 375 °C, the film has the best crystal quality. By the electrical and transmittance measurements the film shows large carrier concentration of 2.00×10²⁰/cm³, Hall mobility of 64 cm²/V s, resistivity of 4.87×10⁻⁴ Ω cm and a high average transmittance over 80% in the visible region together with a direct band gap of 2.43 eV. In view of the Burstein–Moss (BM) shift, theoretical calculations show that the film has a direct band gap of 2.17 eV, close to its intrinsic band gap of 2.2 eV. The photoluminescence (PL) measurement shows that the pure CdO film has no luminescence behavior, but it can alloy with ZnO to realize its applications in luminescent devices.     

无定形金刚石膜的光学性质

采用磁过滤真空溅射离子沉积技术，研究了不同衬底负偏压下制备的样品的吸收光谱和光能隙，用632．8nm的椭圆偏振仪测量了膜的厚度和折射率．结果表明：衬底负偏压Vb在-50—20V范围内制备的样品，其光吸收主要是态的吸收，膜中有较多的SP3组份，光能降为3．1～3．4eV，形成无定形金刚石薄膜（a—D）     

Optical and electrical characterization of CdS thin films

Thin CdS films have been grown by chemical bath (CdCl₂, thiourea, ammonia) deposition (CBD) on SnO₂ (TO)-coated glass substrate for use as window materials in CdS/CdTe solar cells. High-resolution transmission electron microscopy revealed grains with an average size of 10 nm. The structure was predominantly hexagonal with a high density of stacking faults. The film crystallinity improved with annealing in air. Annealing in a CdCl₂ flux increased the grain size considerably and reduced the density of stacking faults. The optical transmission of the as-deposited films indicated a band gap energy of 2.41 eV. Annealing in air reduced the band gap by 0.1 eV. Annealing in CdCl₂ led to a sharper optical absorption edge that remained at 2.41 eV. Similar band gap values were obtained by photocurrent spectroscopy and electroabsorption spectroscopy (EEA) using an electrolyte contact. EEA spectra were broad for the as-deposited and air-annealed samples, but narrower for the CdCl₂-annealed films, reflecting the reduction in stacking fault density. Donor densities of ca. 10¹⁷ cm ^–3 were derived from the film/electrolyte junction capacitance.     

Structure and optical properties of InN and InAlN films grown by rf magnetron sputtering

The structure and optical properties of InN and In-rich InAlN films grown by magnetron sputtering were investigated. The XRD results show that these films are highly c-axis oriented. The film morphology and microstructure of these films were observed by AFM and SEM which reveals that the films grown in island growth mode. Optical properties of these films were studied by absorption method. The band gap energy of the InN film grown under substrate temperature of 400 °C is 1.38 eV. By studying the E _g values of InN films deposited under different substrate temperature, the Burstein-Moss effect on band gap of InN was examined. The significant band gap bowing of our In-rich InAlN films was found to be correlated with the In contents. The bowing parameter of 3.68 eV was obtained which is in agreement with previous theoretical predictions.     

Optical and thermal band gap energy of chemically deposited bismuth(III) selenide thin films

The band gap energy of bismuth(III) selenide in thin-film form was determined using the optical and thermal methods. The optical band gap energy of 0.35 eV was calculated on the basis of the recorded optical spectra in the near-infrared region, within the framework of a parabolic approximation for the dispersion relation, using the equations which arise from Fermi’s golden rule for electronic transitions from valence to conduction band. From the temperature dependence of the dark electrical resistance of the bismuth(III) selenide thin films in the region of intrinsic and extrinsic conduction, a thermal band gap energy of 0.37 eV and an ionization energy of the donor impurity level of 0.13 eV were calculated. The thermal, as well as the optical band gap energy are in excellent agreement with a literature value for bulk bismuth(III) selenide. On the basis of these data, several conclusions on the film microstructure (nanocrystalline versus glassy) are derived and also an estimation of the higher bound to the Bohr’s excitonic radius for bulk Bi₂Se₃ is given.