Upconversion photoluminescence of Er3+ and Yb3+ codoped MoS2 powders.

Er3+ and Yb3+ codoped MoS 2 powders have been fabricated by hydrothermal synthesis. The impact of Er3+ and Yb3+ codoping on the structure, morphology, energy band structure and upconversion photoluminescence properties of samples have been studied by XRD, SEM, TEM, XPS and UPL. XRD results reveal that the crystal structure of samples is well matched with the 2H–MoS 2 , and the crystallinity of MoS 2 –Er:Yb significantly increases after annealing. The morphology of samples prepared by hydrothermal synthesis presents flower-like balls composed of nanosheets, while the annealed MoS 2 –Er:Yb samples are the triangular sheet. A small amount of Er3+ and Yb3+ ions doping has little effect on the band structure of MoS 2 but the number of carriers. The MoS 2 –Er:Yb powders show strong green emission at 528 nm, 549 nm and weak red emission at 662 nm under 800 nm and 980 nm laser light pumping, which stem from the Er3+ transition of (2H 11/2 , 4S 3/2)→4I 15/2 and 4F 9/2 → 4I 15/2. Therefore, the MoS 2 –Er:Yb powders can be a promising material in phosphors, biomedical imaging, dye-sensitized solar cells, etc. • Er3+ and Yb3+ codoped MoS 2 powders have prominent green upconversion photoluminescence. • Annealing can significantly improve the crystallinity and upconversion photoluminescence of MoS 2 –Er:Yb samples. • The introduction of Er3+ and Yb3+ ions effectively increases the number of carriers and decreases the impedance of MoS 2. [ABSTRACT FROM AUTHOR]