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-xS, into a single nanocrystal, led to a unique ternary multi-node sheath ZnS–CdS–Cu
2-xS 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-xS 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.
DOI: 10.1002/anie.201601865
http://onlinelibrary.wiley.com/doi/10.1002/anie.201601865/full