Air-processed semitransparent organic solar cells with tunable color

Semitransparent bulk-heterojunction (BHJ) solar cells have attracted considerable attention owing to their potential applications in photovoltaic devices. In this work, we demonstrate a novel approach to developing semitransparent and color-tunable solar cells using a MoO₃/metal/MoO₃ structure as the device electrode. By changing the type of metal used in transparent anode stack, the transmission spectra of the semitransparent cells could be tuned over the visible-light region (400–750 nm). Semitransparent solar cells with blue–green, green, and greyish–green color showed bifacial energy generation when illuminated from either the bottom or top side. Our semitransparent color-tunable solar cells fabricated in air showed an average efficiency of 3% under AM 1.5G illumination.