Ultrafast carrier dynamics in CdS@CdSe core-shell quantum dot heterostructure

Semiconductor quantum dots (QDs) have aroused great fundamental and technological interest due to their novel size-tunable optical properties, and the resulting potential applications in photonics, photoelectronics and biomedicine. In this study, uniform, ultrasmall, well-defined CdS@CdSe core-shell QDs are successfully synthesized by a hot injection method for ultrafast carrier dynamics activities. Femtosecond transient absorption studies show that the bleach recovery time of the CdS@CdSe QDs increases with the thickness of the CdSe shell. In addition, theoretical calculations were carried out to reveal this characteristic. The slower carrier relaxation of the CdS@CdSe QDs indicates its great potential applications from light-emitting diodes to photodetectors and photovoltaics. In short, this work provides a valuable reference platform for the application of core-shell QDbased heterostructure in optics and optoelectronics.

Automated summary

This study successfully synthesized CdS@CdSe core-shell quantum dots and revealed their characteristics through femtosecond transient absorption studies and theoretical calculations, indicating their potential applications in optoelectronics and photovoltaics.