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

Abstract

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.

CoP3 Quantum Dots Decorated on CdZnS Nanorods as Z-Scheme p–n Heterojunctions for Photocatalytic H2 Production

“…In various types of heterojunctions, a p-type semiconductor and an n-type photocatalyst could generate a p–n heterojunction. Because of the large potential difference in their Fermi levels, a strong internal electric field could be generated in the heterojunction, so it has been widely studied . CdZnS is an n-type semiconductor; the p–n heterojunction of its and p-type semiconductors has been extensively studied.…”

Ultrafast Electron and Hole Transfer and Efficient Charge Separation in a Sb2Se3/CdS Thin Film p–n Heterojunction

“…We have performed TA spectroscopy to probe the charge carrier dynamics in the Sb 2 Se 3 /CdS heterojunction to gain more insight into photophysical processes. TA spectroscopy has proven to be an indispensable tool for monitoring charge transfer dynamics within the Sb 2 Se 3 /CdS heterojunction system, offering invaluable insights into both single-junction and heterojunction systems. − The samples are excited with a 410 nm pump pulse, and a change in the absorbance (Δ A ) of the probe beam in the sample in the presence and absence of a pump pulse is monitored. The TA spectrum of the Sb 2 Se 3 film displayed in Figure A shows a negative photoinduced bleach signal peaking around 579 nm, which is far from the optical band gap of Sb 2 Se 3 (1.3 eV, 950 nm), representing excited-state bleaching and a positive photoinduced absorption (PIA) signal with a peak located at 680 nm .…”