含EDOTBT结构单元低能隙聚合物的合成及性能

采用Heck反应制备了以3,4-乙撑二氧噻吩(EDOT)为供体,苯并噻二唑(BT)为受体的D-A型单体4,7-二(3,4-乙撑二氧噻吩)-苯并噻二唑(EDOTBT);采用Suzuki反应合成了一种低能隙的共轭聚合物4,7-二(3,4-乙撑二氧噻吩)-苯并噻二唑-芴共聚物(PEDOTBTF6)。通过核磁共振、热失重、凝胶渗透色谱、紫外-可见光光谱、循环伏安等对其进行了分析研究。结果表明,成功合成了单体EDOTBT及共轭聚合物PEDOTBTF6,所得共聚物具有较高的相对分子质量,在有机溶剂中具有较好的溶解性,且具有良好的热稳定性。PEDOTBTF6具有较低的能带隙,其光学带隙宽为1.65eV。通过循环伏安法测得其HOMO和LUMO能级分别为-5.23eV,-3.58eV。由该共聚物制备的聚合物太阳能电池具有良好的光电性能。初步研究表明,当退火温度为160℃,退火时间为20min时,所得到的聚合物太阳能电池的短路电流(Jsc)为1.6mA/cm2;开路电压(Voc)为0.5V;光电转换效率(PCE)为0.21%。     

基于咔唑的共轭聚合物材料的合成及性能研究

由咔唑以及3-噻吩甲酸出发,经过合理的化学修饰,合成了单体4,7-二溴正辛基咔唑M1和单体1,5-二(正三正丁基锡)-4,8-二(正十二烷氧基)苯并[1,2-b∶4,5-b’]二噻吩M2,然后单体M1与单体M2通过Suzuki偶联聚合合成了共轭聚合物P1。并对聚合物P1进行了一系列的结构表征和性能测试,结果表明P1的光学能带隙为1.56eV,电化学能带隙为1.57eV,5%热失重温度分别为314℃,显示出了良好的光学性能、热稳定性和电化学氧化还原性能。     

可交联的聚3-(4-叠氮基苯甲酰氧基乙基)噻吩的合成及性能

采用FeCl3作为催化剂的氧化偶联聚合法合成了具有交联活性的聚3-(4-叠氮基苯甲氧基乙基)噻吩(P3AET)。用核磁共振、红外光谱、凝胶液相色谱、热重分析、差示扫描量热法、紫外-可见光光谱和循环伏安法表征了聚合物的结构、热稳定性能、交联特性和光电性能。结果表明,P3AET的氯仿溶液的紫外吸收区域为340 nm~550 nm,最大吸收峰在420 nm左右处,聚合物热交联温度约为170℃,电化学禁带宽度约为1.96 eV。P3AET有望作为聚合物太阳能给体材料。     

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。     

双极性菲并咪唑类有机发光材料的合成与性能

以咔唑、菲醌等为原料合成了三种菲并咪唑类有机小分子3a、3b和3c,并研究了其光谱、电化学和热稳定性。结果表明,化合物3a、3b和3c在二氯甲烷稀溶液中属于近紫外发射,而在薄膜状态下发出蓝色荧光;循环伏安法检测表明,3a、3b和3c的HOMO能级均在-5.88~-5.99eV之间,与阳极ITO的能级相匹配,LUMO能级均在-2.64~-2.77eV之间,接近于常用的电子输入材料PBD(-2.82eV),因此这三种化合物同时具有空穴传导和电子传导的双极性质;3a、3b和3c的热分解温度均在300℃以上,热稳定性优良。综上所述,3a、3b和3c是一类具有潜在应用前景的新型双极发光材料。     

新型三元聚合物给体材料的合成及在有机太阳能电池中的应用

以吡咯并[3,4-c]吡咯二酮(DPP)为A单元,苯并[1,2-b∶4,5-b′]二噻吩(BDT)和萘为D单元,合成了一种新型2D/A型三元共轭聚合物太阳能电池给体材料(PDPP-BDT-NT),通过核磁共振氢谱(1 H NMR)对其结构进行了表征,通过热重分析、紫外-可见吸收光谱(UV-Vis)、循环伏安法对其热学性质、光物理性能及能级结构进行了研究。PDPP-BDT-NT具有较好的热稳定性,热分解的温度为401℃,有较宽的吸收光谱,可覆盖300~900nm,最高占据轨道(HOMO)能级为-5.35eV。以聚合物PDPP-BDT-NT为给体材料,PC60BM为受体材料,制备了一系列有机聚合物太阳能电池,在大气质量(AM)为1.5G,功率为100mW·cm-2模拟的太阳光照射下,有机聚合物太阳能电池的光电转化效率(PCE)可达2.09%。甲醇处理后,有机聚合物太阳能电池的PCE可达2.34%。     

新型主链含方酸菁的低能隙烷基芴共聚物的合成及性质

用微波法快速地合成了单体方酸菁染料,并首次通过Suzuki偶联将其键合到聚芴的主链上,目标共聚物通过红外和核磁对其进行了表征。聚合物P1和P2的热分解温度分别为465.3℃和423.2℃,玻璃化温度分别为183.4℃和142.6℃,具有良好的热稳定性和加工性能。该类材料对太阳光的吸收在300nm~900 nm范围,覆盖了整个可见光区域和部分红外区域,电化学分析表明其具有1.46 eV和1.52 eV的低能隙。     

N掺杂P25可见光响应型光催化剂的制备及性能

以P25为改性对象,尿素为N源,采用研磨-煅烧法制备了具有可见光活性的N掺杂改性P25材料(N-P25).采用XPS电子能谱、X衍射、紫外-可见吸收光谱和透射电镜对催化剂的结构进行表征,并考察了N-P25材料在可见光催化下对亚甲基蓝的降解性能.结果表明,XPS检测发现N-P25在399eV处出现一个N1s峰,N1元素的百分比为0.39％,表明N是通过填隙式的掺杂进入P25,以Ti-O-N键存在,改变了P25的能级结构,诱导其发生红移,在可见光下产生光催化活性.光催化降解试验表明,当煅烧温度为400℃时制备的样品在可见光下反应3h对亚甲基蓝的降解率达到最大值,为60.59％.     

含酒石酸基元的液晶单体及其聚合物的合成与表征

合成了一种以酒石酸为中心的新型工字型液晶单体2,3-二乙酰氧基-1,4-丁二酸对烯丙氧基苯甲酸对苯二酚酯(M1),将其与手性液晶单体4-烯丙氧基苯甲酸胆甾醇酯(M2)共聚,得到侧链液晶聚合物P1～P8。通过红外光谱(FT-IR)、核磁共振(1H-NMR)、偏光显微镜(POM)、差示扫描量热分析(DSC)和X射线衍射(XRD)等手段对所获单体及聚合物的结构和液晶相行为进行了表征。结果表明,液晶单体M1具有近晶相扇形、纹影织构,手性单体M2具有胆甾相油丝织构。聚合物P1～P8出现胆甾相的Grandjean织构,随着单体M1含量的增加,聚合物P1～P8的Tg呈上升趋势,液晶区间变窄。     

羟乙基聚芴材料合成与表征

以2,7-二溴-9,9-二(2-羟乙基)-芴和2,7-双硼酸酯-(9,9-二辛基芴)为单体,通过Suzuki聚合反应合成一种蓝光聚(9,9-二羟乙基-2,7-芴)-2,7-(9,9-二辛基芴)(PFOH),采用1HNMR和热重分析对其进行表征,PFOH聚合物具有良好的热稳定性,通过紫外-可见吸收光谱(UV-vis)、光致发光光谱(PL)表征了聚合物的光物理性能,采用循环伏安法通过计算得知聚合物PFOH光学带隙Eg为2.90eV,EHOMO=-5.46eV,ELOMO=-2.56eV。     

基于噻吩-苯非对称单元的DPP类聚合物给体材料的合成及光伏性能

为了优化聚合物太阳能电池的光伏性能,设计合成了一种基于噻吩-苯非对称单元的二酮吡咯并[3,4-c]吡咯(DPP)类聚合物给体材料(PDPP-PT).非对称结构的设计使得该聚合物具有较好的分子堆积,有利于器件的制备.该聚合物具有范围在300~900 nm的宽吸收光谱、1.5 eV的窄光学带隙.在器件性能方面,活性层厚度达260 nm时,测得开路电压(Voc)为0.68 V,光电转换效率(PCE)为1.51%.因此,PDPP-PT给体材料在制备厚活性层太阳能电池时具有一定的优势并为聚合物给体材料的分子设计提供了一种新的思路.     

Synthesis of fluorene-based semiconducting copolymers for organic solar cells

Semiconducting polymers composed of 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)dithiophenes (F8T2s) and (2E,2'E)-3,3'-(2,5-bis(octyloxy)-1,4-phenylene) bis(2-(5-bromothiophene-2-yl)acrylonitrile)s (OPTANs) have been synthesized through Pd(O)-catalyzed Suzuki coupling polymerization by controlling the monomer ratio. The synthesized polymers were confirmed to exhibit good solubility in common solvents, simple processability, and thermal stability up to 350 degrees C. The highest occupied molecular orbitals (HOMOs), lowest unoccupied molecular orbitals (LUMOs), and optical band-gap energies were determined using cyclic voltammetry (CV) and UV-visible spectrometry. The synthesized polymers showed their maximum absorption and edge at around 520 and 650 nm, respectively. The optical band-gap energies of the polymers were determined to be 1.89 eV. Bulk heterojunction organic solar cells were fabricated using the conjugated polymer as the electron donor, and 6,6-phenyl C61-butyric acid methylester (PC61BM) or 6,6-phenyl C71-butyric acid methylester (PC71BM) as the electron acceptor. The power conversion efficiencies (PCEs) of the solar cells based on polymer:PC71BM (1:1) and polymer:PC71BM (1:2) were 0.68% and 1.22%, respectively, under air mass 1.5 global (AM 1.5 G) illumination at 100 mW/cm2.     

Diketopyrrolopyrrole-containing oligothiophene-fullerene triads and their use in organic solar cells

We report the characterization of a series of oligothiophene-diketopyrrolopyrrole-fullerene triads and their use as active materials for solution processed organic solar cells (OSCs). By incorporating the diketopyrrolopyrrole (DPP) core with electron rich oligothiophene units and electron withdrawing fullerene units, multifunctional electronic molecules have been prepared; these molecules show high solubility in common organic solvents, excellent photophysical properties with high extinction coefficients (1 × 10(4) to 1 × 10(5) M(-1) cm(-1)) and broad absorption spectra coverage (250-800 nm), as well as suitable molecular orbital energy levels (HOMO of approximately -5.1 eV, LUMO of approximately -3.7 eV). Solution-processed thin-film organic field effect transistors (OFETs) from these triads revealed good n-type characteristics with electron mobilities up to 1.5 × 10(-3) cm(2) V(-1) s(-1). With these multifunctional triads, single-component OSCs have been fabricated, exhibiting power conversion efficiencies (PCEs) of up to 0.5 % under AM 1.5 G simulated 1 sun solar illumination. Blending these molecules with poly(3-hexylthiophene) (P3HT) afforded bulk heterojunction OSCs with PCEs reaching as high as 2.41%.     

Perspectives on SnSe-based thin film solar cells: a comprehensive review

Currently, selenium (Se)-based compound semiconductors (CISe, CIGSe and CZTSe) are considered as the active materials in the photovoltaic world. However, these materials exhibit couple of issues related to stoichiometry maintenance and scarcity of their constituent elements (In, Ga), which limit their massive production for future energy demands. These issues could be rectified by introducing a non-toxic, inexpensive and earth-abundant binary material. One such material is a tin monoselenide (SnSe), which exhibits a high chemical stability along with attractive physical properties namely, suitable band gap (1.3 eV), high absorption coefficient (10⁵ cm^?1) and p-type conductivity. These properties indicate SnSe as a competitive substitute in place of conventional absorbers in thin film solar cells. Despite of its remarkable properties, only a few reports were published on the fabrication of SnSe-based solar cells with poor efficiency (≤1 %). This indicates a need to review on the physical properties of SnSe and its device structures in a deeper sense. In this context, the present review describes the different methods of preparation of SnSe films and their physical properties along with the details of photovoltaic device fabrication. We highlighted the different factors that are limiting the efficiency of SnSe solar cells, and a few suggestions were included to overcome these problems for further improvement of these cells. This review will enrich and stimulate the readers to further investigate the growth of SnSe thin films and their devices, for the development of >20 % efficient SnSe solar cells.     

可溶性聚噻吩甲烷的制备与光学性能

利用噻吩和对二甲氨基苯甲醛在酸性条件下共聚,制备了一种具有可溶性、分子链部分共轭的聚噻吩甲烷衍生物。采用傅里叶变换红外光谱、紫外-可见吸收光谱、荧光光谱、热重分析和X射线衍射谱对聚合物的分子结构、光学性能、热稳定性能及聚集态结构进行了表征和分析。由紫外-可见吸收光谱可得,该聚合物的光学禁带宽度为1.3 eV,属于窄带隙聚合物。荧光光谱显示,该聚合物溶液在480 nm可见光的激发下,出现约600 nm的发射光,说明该聚合物为橙黄色的荧光材料。X射线衍射谱中17.3°附近存在1个较为尖锐的衍射峰,表明该聚合物聚集态结构为部分结晶态。     

Synthesis, characterization, and nonlinear optical properties of donor–acceptor conjugated polymers and polymer/Ag nanocomposites

Two new donor–acceptor (D–A) conjugated polymers P1 and P2 containing 3,4-didodecyloxythiophene and 1,3,4-oxadiazole units are synthesized via Wittig reaction methodology. Cyclic voltammetry studies reveal that the polymers are both p and n dopable, and possess low-lying LUMO energy levels (?3.34?eV for P1 and ?3.46?eV for P2) and high-lying HOMO energy levels (?5.34?eV for P1 and ?5.27?eV for P2). The optical band gap of the polymers is in the range of 2.25–2.29?eV, calculated from the onset absorption edge. The polymers emit orange to yellow light in the film state when irradiated with a UV light. The synthesized polymers are used to prepare polymer nanocomposites with different wt% of silver nanoparticles. The polymer nanocomposites are characterized by UV–Vis absorption spectroscopy, field emission scanning electron microscopy, and thermogravimetric analysis. Both polymers and polymer/Ag nanocomposites show good thermal stability with onset decomposition temperature around 300?°C under nitrogen atmosphere. The nonlinear optical properties of polymers and polymer/Ag nanocomposites are measured by Z-scan technique. Both polymers and polymer nanocomposites show a good optical limiting behavior. Nearly five times enhancement in the nonlinear optical properties is observed for polymer/Ag nanocomposites. The value of effective two-photon absorption coefficient (β) is in the order of 10^?10–10^?11?m/W. These results indicate that the synthesized polymers (P1 and P2) and their Ag nanocomposites are expected to be good candidates for application in photonic devices.     

Vacuum-deposited planar heterojunction polymer solar cells

The vacuum thermal evaporation of poly(3-hexylthiophene) (P3HT) for application in photovoltaic cells is demonstrated. Structural changes before and after evaporation are determined using GPC, UV-vis absorption spectroscopy, NMR, and FTIR. GPC showed that the polymer molecular weight is reduced during evaporation, leading to a blue-shift of the absorption spectra. FTIR and NMR were used to examine the change in chemical structure: it was found that conjugation remains mostly intact; however, the conjugation length decreases and side chains dissociate from the backbone. Bilayer heterojunction solar cells were fabricated by sequential deposition of P3HT and C?? and the photovoltaic response measured.     

High-Performance All-Polymer Solar Cells Enabled by n-Type Polymers with an Ultranarrow Bandgap Down to 1.28 eV

Compared to organic solar cells based on narrow-bandgap nonfullerene small-molecule acceptors, the performance of all-polymer solar cells (all-PSCs) lags much behind due to the lack of high-performance n-type polymers, which should have low-aligned frontier molecular orbital levels and narrow bandgap with broad and intense absorption extended to the near-infrared region. Herein, two novel polymer acceptors, DCNBT-TPC and DCNBT-TPIC, are synthesized with ultranarrow bandgaps (ultra-NBG) of 1.38 and 1.28 eV, respectively. When applied in transistors, both polymers show efficient charge transport with a highest electron mobility of 1.72 cm² V⁻¹ s⁻¹ obtained for DCNBT-TPC. Blended with a polymer donor, PBDTTT-E-T, the resultant all-PSCs based on DCNBT-TPC and DCNBT-TPIC achieve remarkable power conversion efficiencies (PCEs) of 9.26% and 10.22% with short-circuit currents up to 19.44 and 22.52 mA cm⁻², respectively. This is the first example that a PCE of over 10% can be achieved using ultra-NBG polymer acceptors with a photoresponse reaching 950 nm in all-PSCs. These results demonstrate that ultra-NBG polymer acceptors, in line with nonfullerene small-molecule acceptors, are also available as a highly promising class of electron acceptors for maximizing device performance in all-PSCs.     

低带隙共轭聚合物的合成及光学性质

在钯催化剂的作用下,通过4,7-二溴[2,1,3]苯并噻二唑与2,5-二乙炔基-3-辛基噻吩的偶联反应,合成了一种新的共轭高分子PTE-BT.采用紫外可见吸收光谱及荧光光谱对其光学性质进行了研究.紫外可见吸收谱结果表明,PTE-BT的固体膜光学带隙为1.86 ev;TiO2/PTE-BT共混固体膜的荧光发射谱结果表明,电子供体PTE-BT分子与电子受体TiO2分子间存在有效的电子转移.