硅纳米线/非光活性透明导电高分子体相异质结的构筑及其光电转换性能研究

Solution-processed solar cells have been considered as a promising way for obtaining low-cost sustainable energy. In recent years, hybrid bulk heterojunction solar cells based on blend composites of inorganic nanomaterials and conjugated polymers have received much attention for their advantages of low-cost solution-processability, feasibility of making larger-area devices and stability over purely organic devices. However, these efficiencies are much lower than what expected from their theoretical value, mainly due to the recombination loss in the polymer. The proposal suggests fabrication and photo-electric conversion performance research of silicon naowire/non-photoactive transparent conductive polymer bulk heterojunction to solve this issue. It is proposed that based on unique properties of Si at wide spectral absorption and high carriers mobility; As well as the light absorption and carriers separation efficiency could be largely improved by surface modifying. The silicon nanowire /non-photoactive polymer bulk heterojunction was designed to avoid the issue of recombination loss and short device lifetime brought by the photoactive polymer. The breakthroughs in this area will provide new theoretical and experimental basis for obtaining high efficiency, low-cost, stable hybrid bulk heterojunction solar cells.

溶液法制备太阳能电池被公认为是一种获得廉价能源的理想方式。近几年，基于无机纳米材料/共轭高分子的有机无机杂化体相异质结电池由于拥有低成本的溶液法制备过程，容易制备大面积器件以及比纯有机器件更稳定的优势，受到广泛关注。然而，目前该类器件的效率还远低于理论值，这主要是由于作为主要光活性材料的半导体高分子中的激子复合造成的能量损失。针对该瓶颈问题，在本申请中我们提出硅纳米线/非光活性透明导电高分子体相异质结的构筑及其光电转换性能研究的创新研究思路。拟基于硅纳米线宽光谱吸收，较高的载流子传输效率和经过表面修饰后可以大大增强光吸收能力和载流子分离效率等优势，与非光活性的透明导电高分子共同构筑杂化体相异质结以避免光活性高分子带来的复合能量损失和器件寿命问题。此方面的研究突破将为获得高效，低成本，稳定的太阳能电池提供新的理论和实验基础。

通过设计有机/无机杂化结构，再将阵列结构硅纳米线组装在非光活性的导电聚合物薄膜中，将此薄膜从硅纳米线衬底上剥离，构筑出柔性的有机/无机杂化太阳能电池。相对于传统的有机/无机杂化电池中使用的光活性半导体材料，透明导电高分子不影响硅材料对可见光的吸收，同时其高的电输运能力增强了硅纳米线中光生载流子的快速分离，因此能极大的提高太阳能转换效率。另外此方法能够将电池的硅材料用量大大降低，因此还具有降低太阳能转换成本的潜力。在进一步的研究中，我们通过在硅表面修饰Pt金属纳米颗粒，将电池效率进一步提高。通过在硅纳米线表面构筑有机/无机杂化结构，稳定了硅纳米线的表面化学性质，增强了它的可见光催化制氢和光伏转换能力，研究结果对于高效太阳能转换具有重要的意义。