Improved Doping and Emission Efficiencies of Mn-Doped CsPbCl Perovskite Nanocrystals via Nickel Chloride.

It is challenging to improve the emission efficiency of Mn-doped CsPbCl (Mn:CsPbCl) nanocrystals (NCs) because the excellent optical performances are dependent on high doping efficiency and few defects and traps. Steady-state and time-resolved photoluminescence (PL) spectroscopies were used to investigate the luminescence properties of Mn:CsPbCl NCs with different Mn doping levels synthesized in the presence of nickel chloride. The doping efficiency of Mn ions in Mn:CsPbCl NCs was greatly enhanced in the presence of NiCl, and the PL wavelength of Mn ions was tuned from 594 to 638 nm by varying the concentration of dopant Mn from 0.11% to 15.25%. The high emission quantum yields of Mn:CsPbCl NCs with orange and red emissions peaked at 600 and 620 nm in hexane were 70% and 39%, respectively. The improvement in doping and emission efficiencies of Mn was attributed to the enhanced formation energies of the Mn doping under the Mn and Ni codoped configuration and the resulting reduction of defects and traps in Mn:CsPbCl NCs with incorporation of Ni ions.