2D materials possess significant potential across various applications, with physical and chemical properties that can be effectively modulated by their thickness, enabling tailored optimization for specific uses. For instance, 2D monolayers are ideal for transparent and flexible electronics, while 2D multilayers are more suitable for solar cells and high-speed devices. Although scalable methods for synthesizing large-area 2D materials and their applications have been developed, most research has focused on monolayers, with comparatively limited efforts directed toward multilayers. This review provides an overview of the emerging field of 2D multilayers, revisiting the analysis of layer-dependent properties to determine the optimal material thickness for various applications. It introduces representative techniques for synthesizing 2D multilayer films and presents applications where multilayer structures demonstrate superior performance compared to monolayers, particularly in electronics and optoelectronics. The review advocates for the development of synthesis and integration methods for 2D multilayers, calling for a shift in research focus toward these materials to enhance their technological impact and unlock new industrial applications.
