Doping of InP quantum dots and its optical properties

Abstract

The Li+ and Zn2+ doped InP quantum dots (denoted as Li: InP QDs and Zn: InP QDs) were synthesized via an in-situ nucleation doping approach. Effects of dopant on the structure, size and optical property of QDs were investigated in detail. The results showed that Li: InP and Zn: InP QDs were well crystallized with uniform size. In the case of Li+ dopant, Li+ did not enter the InP lattice, but inhibited the nucleation and growth of InP QDs. Blue shifts were observed in UV-Vis absorption spectra and fluorescence spectra due to the quantum size effect of Li: InP QDs. Compared with Li+, Zn2+ dopant also inhibited nucleation and growth of InP QDs, but InP/Zn3P2/ZnO composite was produced with a core-shell structure, resulted in a great improvement of photoluminescence (PL) intensity. Especially when the doping concentration of Zn/In atomic ratio was 0.2, the PL intensity was increased more than 100 times as compared with that of undoped InP QDs. This work may provide a considerable approach to the synthesis of short-wavelength InP QDs.