二烷硫基噻吩—二噻并苯并二噻吩基共轭聚合物的合成与研究

发布时间：2018-07-25 14:37

【摘要】：活性层材料是聚合物太阳能电池器件的核心部分,其性能的优化和改善对提高太阳能电池器件的效率有着很重要的意义。通过对活性层中的给体材料的优化设计,可以得到光电性能优异的有机太阳能电池器件。本文是在DTBDT单元的5,10位上引入噻吩硫的烷基侧链,首次合成出一种新的电子给体单元DTBDT-TS。将给体单元DTBDT-TS与受体单元(2,1,3-苯并噻二唑/5,6-双氟代2,1,3-苯并噻二唑、萘并[1,2-c:5,6-c']双[1,2,5]噻二唑、噻并异靛蓝等的衍生物)通过Stille偶联反应合成出了系列窄带隙D-A型共聚物,并对聚合物的热稳定性、吸收光谱和电化学性能进行表征;对聚合物的分子最优模型、二面角和HOMO、LUMO能级轨道进行估算,对聚合物的光伏性能进行初步的研究。首先,将烷硫基噻吩侧链引入到DTBDT单元上,制备了电子给体单元DTBDT-TS。以DTBDT-TS与缺电单元BT与FBT,2-丁基辛基噻吩作共轭π桥,通过Stille偶合得到两种窄带隙共轭聚合物PDTBDT-TS-DTBT和PDTBDT-TS-DTFBT。表征结果表明共轭聚合物PDTBDT-TS-DTBT和PDTBDT-TS-DTFBT在300-800 nm范围对太阳光有吸收,光学带隙分别为1.67和1.68 eV,LUMO分别为-3.55和-3.71 eV;HOMO分别为-5.22和-5.39eV。但是在溶解性能实验中发现上述聚合物在常用有机溶剂中溶解性差。因此引入更大烷基侧链(2-辛基十二烷基),通过对受体单体的优化设计来改善聚合物的溶解性,成功合成了两种溶液加工性能改善的聚合物PDTBDT-TS-DTBT2和PDTBDT-TS-DTFBT2,并且热稳定性没有降低、光学带隙略有增大、能级保持恒定。聚合物太阳能器件结构为ITO/PFN/Polymer:PC61BM/MoO3/Ag。聚合物太阳能电池光活性层PDTBDT-TS-DTBT2:PC61BM=1:1.5共混膜,同时加入3%DIO时,器件的光电转换效率PCE最高为3.47%(其VOC=0.81 V,JSC=6.53 mA/cm2,FF=65.69%)。聚合物太阳能电池光活性层PDTBDT-TS-DTFBT2:PC61BM的质量比为1:1.5,同时加入3%DIO时,器件的光电转换效率PCE最高为4.61%(其VOC=0.88 V,JSC=9.27 mA/cm2,FF=56.48%)。含氟取代的聚合物表现出更为优异的光伏性能和更好的分子平面性,有利于载流子的传输,从而获得高的短路电流,最终获得较高的能量转换效率。其次,将给体单元DTBDT-TS与受体单元DTNTHD通过Stille偶联反应得到聚合物PDTBDT-TS-DTNTHD,该聚合物有良好的成膜加工性能,热分解温度为347℃,在可见光区有较强的吸收,吸收范围从300至800 nm,薄膜状态下的最大吸收峰位于672nm处,光学带隙为1.67 e V。HOMO和LOMO能级分别为-5.35和-3.68 eV。以PDTBDT-TS-DTNTHD:PC61BM共混膜为活性层,加入3%DIO后器件的开路电压和短路电流均增大,获得能量转换效率最高为2.03%(其VOC=0.78 V,JSC=6.80 mA/cm2,FF=38.3%)。再次,将给体单元DTBDT-TS与受体单元TIID通过Stille偶联反应得到聚合物PDTBDT-TS-TIID,该聚合物具有良好的成膜加工性能,热分解温度为344℃。聚合物PDTBDT-TS-TIID的光学带隙仅为1.28 eV,在可见光区内有较强的吸收,吸收范围从300拓展至1000 nm,HOMO和LUMO能级分别为-5.28和-4.00 eV。以PDTBDT-TS-TIID:PC61BM=1:1.5共混膜为活性层,加入3%DIO制备的太阳能器件能量转换效率最高为0.66%(其VOC=0.47 V,JSC=3.13 mA/cm2,FF=44.84%)。
[Abstract]:The active layer material is the core part of the polymer solar cell device. The optimization and improvement of its performance is very important to improve the efficiency of the solar cell device. By optimizing the material in the active layer, the organic light energy battery device with excellent photoelectric performance can be obtained. This paper is in the 5,10 of the DTBDT unit. By introducing an alkyl side chain of thiophene sulfur, a new electron donor unit, DTBDT-TS., was synthesized for the first time by DTBDT-TS and receptor units (2,1,3- benzothiazole /5,6- bis 2,1,3- benzothiazole two azole, naphthalene and [1,2-c:5,6-c'] double [1,2,5] thiothiazoles, thioisoindigo and other derivatives) synthesized by Stille coupling reaction. The D-A type copolymer of narrow band gap is listed, and the thermal stability, absorption spectrum and electrochemical performance of the polymer are characterized. The molecular optimal model of the polymer, the dihedral angle and the HOMO, LUMO energy level orbit are estimated, and the photovoltaic performance of the polymer is preliminarily studied. First, the alkthiophene side chain is introduced to the DTBDT unit and the electricity is prepared. The subunit DTBDT-TS. is used as a conjugate bridge with DTBDT-TS and BT and FBT, 2- butyl octyl thiophene, and two narrow band gap conjugated polymers, PDTBDT-TS-DTBT and PDTBDT-TS-DTFBT., are characterized by Stille coupling. The results show that the conjugated polymer PDTBDT-TS-DTBT and PDTBDT-TS-DTFBT are absorbed to the sun light in the 300-800 nm range and the optical band gap is in the band gap. 1.67 and 1.68 eV, respectively, LUMO is -3.55 and -3.71 eV, respectively, HOMO is -5.22 and -5.39eV., respectively, but it is found that the solubility of the polymer in the common organic solvent is poor in the dissolution test. Therefore, the larger alkyl side chain (2- octyl twelve alkyl) is introduced, and the solubility of the polymer is improved by optimizing the receptor monomer. Two kinds of polymer PDTBDT-TS-DTBT2 and PDTBDT-TS-DTFBT2 were synthesized, and the thermal stability was not reduced, the optical band gap was slightly increased and the energy level kept constant. The structure of the polymer solar device was the PDTBDT-TS-DTBT2:PC61BM=1:1.5 blend film of the photoactive layer of the ITO/PFN/Polymer:PC61BM/MoO3/Ag. polymer solar cell, At the same time, when 3%DIO is added, the photoelectric conversion efficiency of the device is up to 3.47% (its VOC=0.81 V, JSC=6.53 mA/cm2, FF=65.69%). The mass ratio of the photoactive layer PDTBDT-TS-DTFBT2:PC61BM of the polymer solar cell is 1:1.5, and the photoelectric conversion efficiency of the device is higher than 4.61% when the 3%DIO is added. The fluoro substituted polymers show better photovoltaic properties and better molecular planarity, which is beneficial to the transport of carriers, thus obtaining high short-circuit current, and finally obtaining high energy conversion efficiency. Secondly, the polymer PDTBDT-TS-DTNTHD is obtained by coupling reaction of the donor cell DTBDT-TS and the receptor unit DTNTHD, which is the polymer. The compound has good film forming properties, the thermal decomposition temperature is 347 C, the absorption range is stronger in the visible light area, the absorption range is from 300 to 800 nm, the maximum absorption peak in the film state is at 672nm, the optical band gap is 1.67 e V.HOMO and LOMO energy level is -5.35 and -3.68 eV. as the active layer with PDTBDT-TS-DTNTHD:PC61BM blend membrane, adding 3%DIO. The open circuit voltage and short circuit current of the post device all increase, and the maximum energy conversion efficiency is 2.03% (its VOC=0.78 V, JSC=6.80 mA/cm2, FF=38.3%). Again, the polymer PDTBDT-TS-TIID is obtained by Stille coupling reaction between the donor unit DTBDT-TS and the receptor unit TIID. The polymer has a good film forming performance and the thermal decomposition temperature is 344. The optical band gap of the polymer PDTBDT-TS-TIID is only 1.28 eV, which has strong absorption in the visible region, the absorption range is expanded from 300 to 1000 nm, the HOMO and LUMO energy levels are -5.28 and -4.00 eV., respectively, with PDTBDT-TS-TIID:PC61BM=1:1.5 blend membrane as the active layer, and the energy conversion efficiency of the added 3%DIO prepared by 3%DIO is the highest (VOC=0). .47 V, JSC=3.13 mA/cm2, FF=44.84%).
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

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