Optical properties and NIR Photoluminescence of Dy³⁺ doped CdS Q-dots dispersed in borosilicate glass for biophotonics applications

We synthesised CdS Q-dots and Dy³⁺ doped CdS Q-dots dispersed in borosilicate glasses and evaluated their optical and NIR photoluminescence properties. When excited with an 800nm source, new strong photoluminescence emissions from 850 to 1150 nm were observed in the NIR are reported. These new find states may be attributed to NIR virtual or trap states of the CdS S-Qdot. The strong photoluminescence emission spectrum observed from 850 to 950 nm corresponds to electron-hole recombination for as-prepared CdS-Q-dot glasses. However, this photoluminescence emission disappeared upon heat treatment due to photoluminescence emission from defect states.