Improved Doping and Emission Efficiencies of Mn-Doped CsPbCl₃ Perovskite Nanocrystals via Nickel Chloride

Abstract

It is challenging to improve the emission efficiency of Mn-doped CsPbCl3 (Mn:CsPbCl3) 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:CsPbCl3 NCs with different Mn doping levels synthesized in the presence of nickel chloride. The doping efficiency of Mn ions in Mn:CsPbCl3 NCs was greatly enhanced in the presence of NiCl2, and the PL wavelength of Mn2+ 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:CsPbCl3 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 Mn2+ 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:CsPbCl3 NCs with incorporation of Ni2+ ions.