Background

Multiexciton generation (MEG) is promising towards high-efficiency solar cells. Lead chalcogenide nanostructures are good potential candidates for applications in MEG solar cells. We have been successfully synthesized hyperbranched PbSe nanowire networks. Hyperbranched PbSe nanowire networks are synthesized via a vapor-liquid-solid (VLS) mechanism. The branching is induced by continuously feeding the PbSe reactant with the vapor of a low-melting point metal catalyst including In, Ga and Bi. The branches show very regular orientation relationships: either perpendicular or parallel to each other. The diameter of the individual NWs depends on the size of the catalyst droplets, which can be controlled by the catalyst vapor pressure. Electrical measurements across single branched NWs show the evolution of charge carrier transport with distance and degree of branching. Multiexciton generation is currently under investigation