Milk Tea–Colored Perovskite Solar Cells Fabricated Through a Multilayer Film Design

This study presents the fabrication of perovskite thin-film solar cells (PTSCs) with adjustable colors, achieved through a multilayer film design. The multilayer film, comprising Au and indium-tin-oxide (ITO), functions as an adjusted color reflectance (ACR) multilayer film. When the ITO thickness is varied from 100 to 150 nm, the color of the PTSCs can be adjusted from lighter shades that resemble fresh milk tea to darker tones akin to caramel. The color changes that the ACR multilayer film induces correlate well with its reflectance response. Compared with traditional black-colored PTSCs, the milk tea–colored PTSCs maintain a power conversion efficiency of >12%. This achievement suggests the potential for fabricating PTSCs in various colors and patterns that are suitable for use in furnishings, accessories, and other applications.