Efficient red photoluminescence from Al3+ and Cu+ co-doped CdS QDs embedded silicate glasses

Abstract

Embedding CdS QDs into glasses can improve the thermal and chemical stability of QDs, which facilitates their wide and endurable applications such as nonlinear optical devices, optical filters, LED color converter and other optical emitters. Unlike colloid CdS QDs, it is difficult to modify surface states of CdS QDs in glasses by constructing ZnS or Cd1-xZnxS shell. In this work, Cu+ ions doped CdS QDs were precipitated in silicate glasses. It was found that Al3+ ions were simultaneously incorporated into CdS QDs along with Cu+ ions. Incorporation of Al3+ ions into CdS QDs not only lead to well dispersion of Cu+ ions, but also created sulfur vacancies and formed one electron trapping level below the conduction band of CdS QDs, leading to the donor–acceptor photoluminescence with improved photoluminescence quantum yields and thermal stability. Results reported provides an effective method to alleviate the surface defects and improve the photoluminescence quantum yields, promoting their potential applications as color-converting materials for light-emitting diodes.