真空冷喷涂技术制备塑料染料敏化太阳能电池中TiO_2散射层及其性能表征

Preparation and Characterization of TiO_2 Scattering Layer for Plastic DyeSensitized Solar Cells by Vacuum Cold Spray

塑料染料敏化太阳能电池（DSC）由于其质量轻、形状灵活可变、适用于低成本的连续式生产而成为一种很有发展前景的光化学太阳能电池。为了提高电池的效率,在室温下用真空冷喷涂技术将亚微米级制备在TiO2纳米晶体层表面形成一层光散射层。通过研究光散射层的影响以及散射层与纳米晶TiO2层的结合以理解电池效率提高的原因。为了对比,使用乙醇中添加亚微米级Al2O3或TiO2颗粒形成的悬浮液,采用溅射沉积法,制备出两种散射层。结果显示,所有三种散射层对光的反射能力均强于TiO2纳米晶体层。无照电流结果表明NC＋VCSTiO2电池的散射层与TiO2纳米晶体层连接比另外两对组合更有效。因此,由吸附在散射层粒子表面的分子所决定的光诱导电子可以有效转移到TiO2纳米晶体层,并最终输出到外电流回路。假设由于散射效应电池效率提升13%,那么散射层与TiO2纳米晶体层层之间的良好结合贡献10%,最终导致使用NC＋VCS-TiO2散射层的塑料染料敏化太阳能电池效率提升～23%。此外,NC＋VCS-TiO2散射层的抗弯性能优于NC＋SD-TiO2和NC＋SD-Al2O3电池。

Plastic dye-sensitized solar cells （DSCs） are promising photochemical solar cells owing to their light weight, flexibility of shape, and suitability for low cost roll-to-roll production. In order to improve the cell efficiency, light scattering layer was prepared on the surface of the TiO2 nanocrystalline （NC） layer by vacuum cold spray （VCS） at room temperature using submicro-sized TiO2 particles. The influence of the scattering layer and the connection between scattering layer and nano- TiO2 coating was investigated to understand the improvement of the cell efficiency, For comparison, two scattering layers were prepared by a spray deposition （SD） method using an ethanol-based suspension with sub-micrometer Al2O3 particles or TiO2 particles. Results showed that all three layers presented a much higher lightreflecting capability than that of the TiO2 nanocrystalline（NC） layer. The dark current results demonstrated that the connection between the scattering layer and the TiO2 NC layer of the NC＋VCS- TiO2 cell was much more effective than that of the two counterparts. As a result, the photo-induced lectrons denoted by the molecules adsorbed on the particle surface in the scattering layer could successfully transport to the TiO2 NC layer and finally to out circuit. Taking into account the efficiency increment of～13% by the light scattering effect, this good connection between the TiO2 scattering layer and the TiO2 NC layer contributed to an increase in efficiency by 10%, resulting in a total -23% efficiency improvement for the plastic DSCs using VCS- TiO2 scattering layer. Moreover, the bending property of the NC＋VCS- TiO2 cell is much better than that of the NC＋SD TiO2 cell and NC＋SD-Al2O3 cell.