Enhanced photoluminescence efficiencies of CsPbCl3-xBrx nanocrystals by incorporating neodymium ions

Abstract

All-inorganic perovskite nanocrystals (NCs) are emerged as promising materials for illumination and display applications due to their excellent luminescent properties. However, the low photoluminescence quantum yield (PLQY) of violet/blue emission and poor stability of NCs restrict their development. Herein, we report an effective strategy for enhanced PLQY and stability of CsPb(Cl/Br)3 NCs by incorporating Nd3+ ions. It was found that Nd3+ ions could be doped into the host perovskite NC lattice which exists in NCs as Nd3+. The steady-state and time-resolved PL spectra showed the decrease of the defect state density in doped NCs with the increase of Nd content. The maximum PLQY of the as-prepared Nd3+ doped CsPbCl3 NCs was increased up to 58% at the Nd/Pb molar ratio of 3/1. Compared with undoped NCs, the water stability of Nd3+ doped CsPbCl3 NCs was significantly improved. The prepared Nd3+ doped CsPbCl3 NCs were further post-treated by anion exchange reaction with PbBr2 at room temperature. The PL of the as-synthesized Nd3+ doped CsPb(Cl/Br)3 NCs covered the emission range of 408–503 nm, and the maximum PLQY could reached 93%. This work discourses that Nd3+ ions can improve the PLQY and stability of blue and violet perovskite NCs, which will promote their practical application.