Ultrafast Hole Migration at the p-n Heterojunction of One-Dimensional SnS Nanorods and Zero-Dimensional CdS Quantum Dots.

The p-n heterojunctions fabricated from one-dimensional (1D) p-type tin sulfide nanorods (SnS NRs) decorated with n-type zero-dimensional (0D) cadmium sulfide quantum dots (CdS QDs) have gained significant research attention in energy storage devices. Herein, we have successfully synthesized a 1D/0D SnS@CdS heterostructure (HS) using a hot injection method. Structural and morphological studies clearly suggest that CdS QDs are uniformly anchored on the surface of SnS NRs, resulting in intimate contact between two components. The photoluminescence (PL) study revealed the transfer of photoexcited holes from CdS QDs to SnS NRs, which was further confirmed by transient absorption (TA) studies. TA measurements demonstrate the hole transfer from the valence band of CdS QDs to SnS NRs and delocalization of electrons between the conduction band of SnS NRs and CdS QDs in SnS@CdS HS, resulting in efficient charge separation across the p-n heterojunction. These findings will open up a new paradigm for improving the efficiency of optoelectronic devices.