A Chinese research team has developed a sandwich buffer layer, MoOx/Ag/MoOx (MAM), to enhance carrier transport and efficiency in semi-transparent perovskite-silicon tandem solar cells. The layer improved performance and scalability of CsPbI3-based perovskite solar cells, achieving efficiencies exceeding 26% in minimodules. The MAM buffer layer showed long-term stability and scalability, with minimodules retaining over 93% of initial performance after 1,000 hours of storage. The research team aims to further enhance efficiency by finding suitable transparent, cost-effective materials to draw the two devices together in series for large-size tandem modules.