Mn2+ ions doped lead-free zero-dimensional K3SbCl6 perovskite nanocrystals towards white light emitting diodes

Abstract

In recent years, the lead-free zero-dimensional (0D) perovskite nanocrystals (NCs) with isolated octahedral structure have attracted wide attentions due to their unique photoelectric properties, such as the excellent absorption cross-sections, large exciton binding energy and low carrier mobility. However, the emitting wavelength of the lead-free 0D perovskite NCs can only be modulated in the green and blue spectral region. Until now, how to realize the red and white emission in the lead-free 0D perovskite NCs is still a challenge. In this work, the lead-free 0D K3SbCl6 perovskite NCs were firstly developed by the hot injection synthesis method. Through controlling the synthetic temperature, the as-prepared NCs exhibit the blue emission centered at 440 nm with the highest photoluminescence quantum yield (PLQY) of 22.3%. Furthermore, the Mn2+ ions were further doped into 0D lead-free K3SbCl6 perovskite NCs, leading to the additional red light emission attributed to the intrinsic transition (4T1−6A1) of Mn2+ ions. By controlling the Mn2+ ion doping concentration, the white light emission with PLQY of 37.2% was realized. Finally, the white light emitting devices (WLEDs) with the Commission Internationale de L’Eclairage 1931(CIE) of (0.29, 0.28), (0.32, 0.30) and (0.35, 0.30) were fabricated by combining the as-prepared Mn2+-K3SbCl6 perovskite NCs with commercial 365 nm UV light chips. The white-light performances of the as-fabricated WLEDs were modulated with tunable correlated color temperature (CCT) from 8173 to 4779 K, which exhibit the high color-rendering index (CRI) more than 80. These results provide the opportunity for the future applications of 0D lead-free perovskite NCs in the lighting and lasing field of LEDs.