SBIR Phase I: Lateral Collection Polycrystalline Silicon Solar Cells

这个小企业创新研究（SBIR）一期项目描述了一个创新的概念，通过分离吸收长度和少数载流子扩散长度来提高多晶硅太阳能电池的能量转换效率。这种新设计被称为侧向收集。制造路线采用可扩展的技术，如压印光刻和电沉积。主要的研究目标是证明与相同厚度的传统太阳能电池相比，多晶硅侧向收集太阳能电池具有更高的电流。该项目的更广泛/商业影响将是有可能显著提高多晶硅太阳能电池的能量转换效率。降低多晶硅太阳能电池能量转换效率的一个主要因素是电流载流子不能从吸收阳光所需的相对较厚的薄膜中收集。具体来说，多晶硅吸收体的最佳厚度为10微米；然而，只有在距离电极约3微米的范围内产生电流才能被提取出来。解决这一问题的方法是使光吸收方向和载流子收集方向去耦。通过将微尺度的收集结构整合到活性层中，这种横向收集设计确保所有载流子都在收集表面的短距离内产生。该技术产生的电流可能比传统器件多60%，从而产生更高的能量转换效率。

This Small Business Innovation Research (SBIR) Phase I project describes an innovative concept to enhance the energy conversion efficiency of polycrystaline-Si solar cells by separating the absorption length from the minority carrier diffusion length. This new design is called lateral collection. The fabrication route employs scalable technologies such as imprint lithography and electrodeposition. The primary research objective is to demonstrate much higher current with polycrystalline silicon lateral collection solar cells compared to conventional solar cells of the same thickness.The broader/commercial impacts of this project will be the potential to significantly improve the energy conversion efficiency of polycrystalline Si solar cells. A major factor that lowers the energy conversion efficiency of polycrystalline silicon solar cell is that current carriers cannot be harvested from the relatively thick films that are needed to absorb sunlight. Specifically, the optimum polycrystalline silicon absorber thickness is 10 microns; however the current can only be extracted if it is generated within about 3 microns of the electrodes. The solution to this problem is to decouple the directions of light absorption and charge carrier collection. By incorporating microscale collecting structures into the active layer, this lateral collection design ensures that all charge carriers are generated within a short distance of a collecting surface. This technology may produce 60% more current than conventional devices, thus resulting in much higher energy conversion efficiency.