Remarkable Luminescence Regulation Covering Full Visible Wavelength Range of Zero-Dimensional Indium-Based Metal Halides

Recently, there has been a lot of research into the use of zero-dimensional (0D) metal halides as new luminous materials. However, the wide-range tunability of luminescence properties by structural engi-neering need to be explored. Here, we report the vacuum solid-state reaction synthesis of a series of indium-based A3InX6 (A 1/4 K, Rb, or Cs; X 1/4 Cl, Br, or their mixture) 0D metal halide single crystals (SCs). Alkali metal substitution at A site leads to similar luminescence properties but very different stability, among which Rb3InCl6 was the most air stable. Halogen alloying at the X site of Rb3InX6 can produce a luminescence wavelength modulation from 436 to 505 nm. The luminescence wavelength was further extended by Sb3 thorn doping to the 509-622 nm region. Finally, due to the high luminescence tunability covering the full visible wavelength range, we achieved pure white light-emitting diodes utilizing a combination of Rb3InBr2Cl4 and Rb3InBr2Cl4:Sb3 thorn SCs. This work provides a strategy with simultaneous substitution, alloying, and doping to modulate the luminescence properties of 0D lead-free metal halides for a variety of applications. (c) 2023 Elsevier Ltd. All rights reserved.