Discerning the Ultrafast Charge Dynamics in Photostable Perovskite-Carbon Dot Composite Systems: Role of Doped Carbon Dots

Photostable perovskite quantum dot (PQD)-based composite systems have huge potential for optoelectronic and photocatalysis applications. Herein, we have synthesized hydrophobic carbon dots (NC-Dots) and made a composite system with PQD to improve the stability of the material and establish a new generation of advanced materials for future applications. However, there is a lack of fundamental understanding of the dynamics and charge separation mechanism in PQD and NC-Dot-based composite systems, which is essential to interpret the degree of efficiency. In this context, we have also synthesized composites of PQD and different co-doped (boron and phosphorus) NC-Dots to explore the complete scenario of carrier dynamics. This would help in finding the appropriate composite system for photocatalysis. The ultrafast studies show that the carrier-transfer process depends on the dopant of the NC-Dots. The PQD-NC-Dots and PQD-phosphorus doped-NC-Dots (PQD-P-NC-Dots) tend to demonstrate unidirectional carrier transfer, while the PQD-boron-doped C-Dots (PQD-B-NC-Dots) are found to be bidirectional carrier-transfer in the hot states. This is the first investigation on the effect of doped NC-Dots on the multiexciton dissociation in the PQD composite systems that showed a direct relationship with the photocatalytic efficiency. This proof of concept in multielectron dissociation and directional carrier transfer may provide a new approach to improve the efficiency in optoelectronics, photocatalysis, and other similar applications.

Automated summary

Photostable perovskite quantum dot (PQD)-based composite systems have great potential for optoelectronic and photocatalysis applications. Researchers synthesized hydrophobic carbon dots (NC-Dots) and formed a composite system with PQD to enhance material stability and create a new generation of advanced materials. The dynamics and charge separation mechanism in PQD and NC-Dot-based composite systems were investigated, and different co-doped NC-Dots were synthesized to explore carrier dynamics. The findings showed that the dopant of NC-Dots influences the carrier-transfer process in the composite system, highlighting the importance of doped NC-Dots in photocatalysis. This study provides insights for improving efficiency in optoelectronics, photocatalysis, and related applications.