Revealing the Structure–Luminescence Relationship in Robust Sn(IV)-Based Metal Halides by Sb³⁺ Doping

Abstract

Low-dimensional hybrid metal halides are an emerging class of materials with highly efficient photoluminescence (PL), but the problems of poor stability remain challenging. Sn(IV)-based metal halides show robust structure but exhibit poor PL properties, and the structure−luminescence relationship is elusive. Herein, two Sn(IV)-based metal halides (compounds 1 and 2) with the same constituent ((C 6 H 16 N 2 )SnCl 6 ) but different crystal structures have been prepared, which however show poor PL properties at room temperature due to the absence of active ns 2 electrons. To improve materials' PL properties, Sb 3+ with active 5s 2 electrons was embedded into the lattice of Sn 4+ -based hosts. As a result, efficient emissions were achieved for Sb 3+ -doped compounds 1 and 2 with a maximum PL efficiency of 14.28 and 62%, respectively. Experimental and calculation results reveal that the smaller distorted lattice structure of the host could result in the blueshift of the emission from Sb 3+ . Thus, a tunable color from red to orange was realized. Benefiting from the broadband efficient emission from Sb 3+ -doped compound 2, an efficient white light-emitting diode with a high color rendering index of up to 92.3 was fabricated to demonstrate its lighting application potential. This work promotes the understanding of the influence of robust Sn(IV)-based host lattice on the PL properties of Sb 3+ , advancing the development of environmentally friendly, low-cost, and high-efficiency Sn(IV)-based metal halides.