Visibly Transparent Monolithic Perovskite/Organic Tandem Solar Cells Achieving Over 6% Light-Utilization Efficiency

Transparent photovoltaics for solar-window applications must balance human-visible clarity with meaningful power output. Here, we report a selectively absorbing, monolithic perovskite/organic tandem that decouples visible transmittance from photocurrent generation and minimizes voltage loss delivering record light-utilization efficiency (LUE) for visibly transparent (VT) tandem devices. An ultra-wide-bandgap, DMA-alloyed perovskite top sub-cell harvests primarily <∼530 nm, achieving, as a single junction, AVT 65.68% and power conversion efficiency (PCE) 8.23% (LUE 5.46%). Complemented by a ternary PCE10-2Cl:Y6:Y12 bottom stack that minimizes visible absorption while harvesting in the NIR, the tandem reaches PCE 10.91% at AVT 55.39%, yielding LUE 6.04%. To the best of our knowledge, this is the first VT monolithic perovskite/organic tandem to surpass 6% LUE at AVT ≥ 50%, while delivering a record-high open circuit voltage (V_OC) of 2.38 V. These results establish optical-electrical co-design guidelines for high-clarity, power-generating glazing, which explicitly connect materials and interface choices in both sub-cells to energetic disorder, built-in potential, and recombination.