目前，人类生产生活中大部分能源依旧来源于传统化石燃料，如煤、石油、天然气。化石燃料的加工和燃烧会产生大量的空气污染物和废弃物，且化石燃料是不可再生资源，最终将耗尽。太阳能作为一种理想的清洁能源，在能源日益短缺的今天越来越受人们的关注。太阳能的利用方式有很多，其中，太阳能的光电转换，即将太阳辐射能转换成电能的技术近几年来发展迅速，是非常活跃的研究领域。基于共轭聚合物的有机太阳电池是新一代的太阳电池，有机太阳电池相比于无机太阳电池，有机太阳电池具有成本较低、质量较轻和适宜制作大面积柔性器件等优点。目前已报道多种材料能量转化效率已经超过了9%，越来越多的新材料正在被合成并应用在太阳电池中，显示出广阔的发展前景。给体材料是有机太阳电池的核心部分，给体材料的光谱吸收、分子量、能级匹配和可加工等性质对太阳电池的效率有直接的影响。如何综合这些因素提升有机太阳电池的光伏性能是目前研究的热点,而且目前合成给体材料的方法普遍比较复杂。本论文的工作主要是基于影响有机太阳电池的诸多要素设计和合成新型的给体材料来提升有机太阳电池的光电转换性能。通过器件优化，使得到的材料发挥最佳的性能，为有机太阳电池的发展和应用提供一些重要信息。同时我们也探索了利用新的合成方法制备共轭聚合物，以期使聚合物的合成简单化和低成本化。主要内容如下：1. 设计合成了给体单元含氟原子的新型给受体交替共聚物。该聚合物具有分子量高、溶解性好和能级匹配等优点。将该聚合物应用在正置型体异质结有机太阳电池中，得到了较高的器件效率，在不使用任何添加剂的情况下，得到了开路电压0.90 V，短路电流密度为8.5 mA/cm2，填充因子达到0.60，能量转换效率为5.85%的结果。利用反型体异质结器件对聚合物进行测试，经过优化，得到了开路电压0.92 V，短路电流密度为14.23 mA/cm2，填充因子0.56，光电转化效率为7.34%的结果。这是目前已知的含咔唑单元和苯并噻二唑单元的共轭聚合物获得的最高器件效率。良好的热稳定性和高的光电转换效率显示出了良好的应用前景。2. 利用新的基于Pd催化的C-H活化合成了共轭聚合物并对其进行性能测试。基于一般的合成共轭聚合物的方法，比如Suzuki-Miyaura coupling和Stille-coupling所存在的缺点，尝试了利用Pd催化的C-H活化合成共轭聚合物，并与利用Suzuki-Miyaura coupling得到的共轭聚合物进行比较，根据性质比较分析得到的结果为之后的相关研究探究了方向和需要解决的问题。

Energy is one of the three basic elements to contemporary social development. Currently, the most energy consumption is from traditional fossil fuels. The use of fossil fuel produces large amounts of air pollutants and waste. The fossil fuels are non-renewable resources and it will be use up in the near future. Organic solar cells, one of the methods to use clean and renewable solar energy, as an energy conversion device converts solar energy into electrical energy is developing rapidly.Bulk-heterojunction (BHJ) solar cells based on composites of electron-donating conjugated polymers (donor) and electron-accepting fullerene derivatives (acceptor) show great application prospects for their obvious advantages over traditional silicon-based solar cells, such as low cost, light weight, and high-throughput manufacture. A series of new materials have been synthesized and applied in organic solar cells; and the power conversion efficiencies (PCEs) above 9% have been achieved. Organic solar cells show great prospects in the near future.Conjugated polymers are essential in PSCs in which the absorption, molecule weight, energy level, and processability of the polymers play an important role to the device efficiency. How to combine these factors to achieve high efficiency solar cells has been paid considerable attention. The synthesis of conjugated polymers is general complex and limits the development of PSCs. In this dissertation, novel conjugated polymers have been designed, synthesized and characterized. The photovoltaic performances have been investigated by the fabrication of bulk-heterojunction solar cells. And we also explored new methods to synthesize conjugated polymers. The main results are as follows:1. We have designed and synthesized a new alternate copolymer with fluorine atoms located on the carbazole donor units. The polymer is of high molecule weight, good solubility, and appropriate energy level. Without any additive, we got the conventional structure device with a Voc of 0.90 eV, a Jsc of 10.8 mA/cm2, an FF of 0.60, and a PCE of 5.58%. After optimization, we got the inverted structure device with a Voc of 0.92 eV, a Jsc of 14.23 mA/cm2, an FF of 0.56, and a PCE of 7.34%. To the best of our knowledge, a PCE of 7.39% and hole mobility of 0.16 cm2V−1s−1 are the best results for carbazole and benzothiadiazole based polymers reported up to now Its good thermal stability and high PCE indicated that the material is very promising in practical applications.2. We have designed and synthesized several conjugated polymers by arylation polycondensation and the photovoltaic properties of these polymers have been investigated by fabrication of solar cells. Considering the traditional methods to prepare conjugated polymers, such as Suzuki-Miyaura coupling and here, we synthesize conjugated polymers by direct C-H arylation and compare with the polymers obtained by Suzuki-Miyaura coupling. Probably due to poor structural perfection, the performance of the same materials synthesized by direct arylation is inferior to those synthesize by Suzuki-Miyaura cross-coupling reactions.