Integration of Semiconducting Sulfides for Full‐Spectrum Solar Energy Absorption and Efficient Charge Separation

Abstract The full harvest of solar energy by semiconductors requires a material that simultaneously absorbs across the whole solar spectrum and collects photogenerated electrons and holes separately. The stepwise integration of three semiconducting sulfides, namely ZnS, CdS, and Cu 2− x S, into a single nanocrystal, led to a unique ternary multi‐node sheath ZnS–CdS–Cu 2− x S heteronanorod for full‐spectrum solar energy absorption. Localized surface plasmon resonance (LSPR) in the nonstoichiometric copper sulfide nanostructures enables effective NIR absorption. More significantly, the construction of pn heterojunctions between Cu 2− x S and CdS leads to staggered gaps, as confirmed by first‐principles simulations. This band alignment causes effective electron–hole separation in the ternary system and hence enables efficient solar energy conversion.