Highly efficient warm white light emission in Sb3+-doped (NH4)4CdCl6 metal halides through A-site Rb-alloying regulation

Abstract

Lead-based metal halides are widely investigated and applied in many fields such as light emitting diodes (LEDs), photovoltaic devices, sensors, and solar cells for their superior optical properties. However, the problem of poor stability hinders their further commercial applications. Herein, we report new all-inorganic zero-dimensional (0D) Sb³⁺-doped (NH₄)₄CdCl₆ halides with highly efficient emission and stability. Under UV excitation, the emission efficiency of pristine (NH₄)₄CdCl₆ is extremely low. However, with the introduction of optically active Sb³⁺, the doped (NH₄)₄CdCl₆ showed a bright orange-yellow emission centered at 570 nm, and photoluminescence quantum yield (PLQY) reached up to 62%, which can be attributed to the unique “host–guest” structure of the 0D metal halides. By maintaining the structure type, warm white light could be tuned by A-site Rb alloying, and a PLQY of 71% could be achieved. This work is aimed to explore the emission mechanism of Sb³⁺ doped Cd-based metal halides, which are promising and efficient photoelectric materials with emission of Sb³⁺ triplet states. In addition, this research explored the structural diversity of 0D metal halides, providing design principles for warm white LEDs.