High-brightness green CdSe/ZnS quantum dots stimulated by solar-blind deep-ultraviolet light in optical wireless communications.

ABSTRACT

Ultraviolet-based optical wireless communication (OWC) is emerging as a significant technology for the next-generation secure communication, particularly within the solar-blind spectra. In this study, we have synthesized two types of green-emitting II-VI family colloidal quantum dots (QDs), specifically ZnCdSe/ZnS and CdSe/CdZnS/ZnS QDs, which are stimulated by ultraviolet (UV) and solar-blind deep-ultraviolet (DUV) light, respectively. With a transmission distance of 1.5 m, the maximum data rate of ZnCdSe/ZnS QDs reaches 40 Mb/s, which is below the forward-error-correction (FEC) limit (3.8 × 10-3) when excited by 385-nm UV light. However, both brightness and bit error rate are significantly deteriorated when excited by 280-nm DUV light. Conversely, 28 and 24 Mb/s were attained using CdSe/CdZnS/ZnS QDs under UV and DUV excitation, respectively. Our studies on light-conversion and communication capabilities of green QDs within the DUV OWC system may provide valuable insights for subsequent research in the field.