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All‐inorganic lead‐free perovskite‐derivative metal halides have shown great promise in optoelectronics, however, it remains challenging to realize efficient near‐infrared (NIR) luminescence in these materials. Herein, we report a novel strategy based on Te4+/Ln3+ (Ln=Er, Nd, and Yb) co‐doping to achieve efficient NIR luminescence in vacancy‐ordered double perovskite Cs2ZrCl6 phosphors, which are excitable by a low‐cost near‐ultraviolet light‐emitting diode (LED) chip. Through sensitization by the spin‐orbital allowed 1S0→3P1 transition of Te4+, intense and multi‐wavelength NIR luminescence originating from the 4f→4f transitions of Er3+, Nd3+, and Yb3+ was acquired, with a quantum yield of 6.1 % for the Er3+ emission. These findings provide a general approach to achieve efficient NIR emission in lead‐free metal halides through ns2‐metal and lanthanide ion co‐doping, thereby opening up a new avenue for exploring NIR‐emitting perovskite derivatives towards versatile applications such as NIR‐LEDs and bioimaging. [ABSTRACT FROM AUTHOR]

Luminescent metal halides have attracted considerable attention in next‐generation solid‐state lighting because of their superior optical properties and easy solution processibility. Herein, we report a new class of highly efficient and dual‐band‐tunable white‐light emitters based on Bi3+/Te4+ co‐doped perovskite derivative Cs2SnCl6 microcrystals. Owing to the strong electron‐phonon coupling and efficient energy transfer from Bi3+ to Te4+, the microcrystals exhibited broad dual‐band white‐light emission originating from the inter‐configurational 3P0,1→1S0 transitions of Bi3+ and Te4+, with good stability and a high photoluminescence (PL) quantum yield of up to 68.3 %. Specifically, a remarkable transition in Bi3+‐PL lifetime from milliseconds at 10 K to microseconds at 300 K was observed, as solid evidence for the isolated Bi3+ emission. These findings provide not only new insights into the excited‐state dynamics of Bi3+ and Te4+ in Cs2SnCl6, but also a general approach to achieve single‐composition white‐light emitters based on lead‐free metal halides through ns2‐metal ion co‐doping. [ABSTRACT FROM AUTHOR]