A novel solution processed SiO₂ coating is investigated for use as an interface layer between the substrate and Mo back contact for making CIGS solar cells on flexible SS foils. Prior to deposition of Mo, a ~ 1 μm thick SiO₂ layer is applied on commercially available SS foils using an economical non-vacuum dip coating method. CIGS absorbers as well as complete CIGS solar cells having the structure Mo/CIGS/CdS/i-ZnO/AZO are grown on SS foils with and without the interface layer and their characteristics are compared. The interface layer improves the adhesion and high temperature mechanical stability of Mo back contact. Although phase formation of CIGS absorber is not influenced by the presence of interface layer, the grain structure and surface morphology are positively impacted, resulting in an enhanced solar cell performance. Composition measurements did not reveal any increase of Fe content in the CIGS absorber after the high temperature selenization step. However, the role of interface layer in blocking the diffusion of Fe from the SS substrate is uncertain, as the high-quality Mo back contact itself could be acting as an efficient Fe barrier layer. The interface layer is capable of electrically isolating Mo back contact from the underlying SS substrate, thus offering the prospect of monolithic integration for making lightweight CIGS modules. With a simple and inexpensive deposition process, which can be easily upscaled for large substrates, the dip-coated SiO₂ interface layer could be a suitable alternative for various existing vacuum deposited layers in realizing low-cost flexible CIGS modules.

研究了一种新颖的溶液处理的SiO ₂涂层，用作基底和Mo背接触之间的界面层，以在柔性SS箔片上制造CIGS太阳能电池。在沉积Mo之前，沉积厚度约为1μm的SiO ₂使用经济的非真空浸涂法将有机层涂覆在可商购的SS箔上。在具有和不具有界面层的SS箔上生长CIGS吸收剂以及具有Mo / CIGS / CdS / i-ZnO / AZO结构的完整CIGS太阳能电池，并比较它们的特性。界面层改善了Mo背接触的附着力和高温机械稳定性。尽管CIGS吸收剂的相形成不受界面层的存在的影响，但晶粒结构和表面形态却受到积极影响，从而提高了太阳能电池的性能。高温硒化步骤后，成分测量未发现CIGS吸收器中的Fe含量增加。但是，界面层在阻止Fe从SS衬底扩散方面的作用尚不确定，因为高质量的Mo背接触本身可以充当有效的Fe阻挡层。界面层能够将Mo背接触与下面的SS衬底电隔离，从而为制造轻型CIGS模块提供单片集成的前景。通过简单且廉价的沉积工艺，可以轻松地将其放大以用于大型基板，浸涂式SiO₂接口层可能是实现低成本灵活CIGS模块的各种现有真空沉积层的合适替代方案。