Ni and K ion doped CsPbX3 NCs for the improvement of luminescence properties by a facile synthesis method in ambient air

All-inorganic lead halide perovskite nanocrystals (NCs) as new emerging semiconducting luminescent materials have attracted tremendous attention for designing optoelectronic devices. We have synthesized high quality of the CsPbX3 NCs with tunable entire visible spectral region by a modified lower temperature method, featured with facile, low-cost and easily operating in an open environment without vacuumization or glovebox system. Besides, we have investigated the incorporation of Ni and K ions into CsPbX3 NCs by adjusting all kinds of composition concentration from halogen salts, based on above mentioned preparation method. The absolute photoluminescence quantum yields (PLQYs) of doped CsPbX3 NCs with different dopant (Ni or K ions) concentration were discussed. It is found that a certain amount of doping is beneficial for suppressing the defects and improving the lattice structure of nanocrystals, whereas an excessive dopant may induce quenching centers of the emission. In addition, a glorious absolute PLQYs of doped CsPbX3 NCs can be obtained by our method, especially for CsPbBr3 and CsPbI3 NCs, and nearly reach 80%.