In recent years, Tandem OLED has become a popular choice for high-end screens, finding applications in premium vehicle cabins, flagship smartphones, tablets, and other fields. The concept of Tandem OLED was proposed by Professor Kido from Yamagata University in Japan in 2003. It involves vertically stacking and series connection (Note: ' series connection ' is kept as pinyin here since it's a technical term; in practice, it would be 'series-connected' or simply 'tandem' in context) two or more RGB organic light-emitting units via a charge generation layer to work in series. Compared to traditional single-layer OLEDs, Tandem OLED achieves higher brightness, lower power consumption, and extended lifespan through the superposition of multiple light-emitting units. The principle lies in the fact that, in a dual-layer series-connected structure, each light-emitting unit only needs to bear half the brightness to achieve the same overall brightness, operating in a higher luminous efficiency range and enduring lower electric field strength. This slows down material aging and extends the screen's lifespan. Simultaneously, since the light-emitting task is shared among multiple layers, less current is required to achieve the same brightness, significantly reducing power consumption. For example, Samsung's latest mass-produced series-connected OLED notebook screen has seen its brightness jump from 1100 nits to 1600 nits, with its lifespan more than doubled. Additionally, Tandem OLED inherits the advantages of OLED's self-emission and pixel-level light control, enabling extremely high contrast and pure black representation. Despite its numerous advantages, the manufacturing process of Tandem OLED is complex and challenging, resulting in higher costs. However, with continuous technological advancements and increased production capacity, Tandem OLED is expected to be more widely applied in the high-end display sector in the future.