Organic−Inorganic Layered and Hollow Tin Bromide Perovskite with Tunable Broadband Emission

Recently, layered
perovskites attracted great attention for its
excellent stability and light-emitting property. However, most of
them rely on the toxic element lead and their emission quantum yields
are generally low. Here, a unique hollow two-dimensional perovskite
was developed in which the organic hexamethylene diamines (C6H18N22+) strongly coupled with distorted
tin bromide anions (SnBr64–). This toxic-free
low-dimensional tin perovskite exhibits a broadband emission in the
visible region with a high luminescence quantum yield of 86%. First-principles
calculation indicate the broadband emission is associated with the
recombination of self-trapped excitons. And the emission is related
to the geometry of tin bromide anions. An ultraviolet light-pumped
white light emitting diode with excellent color-rendering index of
94 was fabricated using it together with a commercially available
blue phosphor.

近年来，层状钙钛矿因其优异的稳定性与发光性能受到广泛关注。然而，绝大多数层状钙钛矿依赖有毒元素铅，且其发射量子产率普遍偏低。本研究开发了一种独特的空心二维钙钛矿，其中有机己二胺（C₆H₁₈N₂²⁺）与畸变溴化锡阴离子（SnBr₆⁴⁻）形成强耦合作用。该无毒性低维锡基钙钛矿在可见光波段展现出宽带发射，发光量子产率高达86%。第一性原理计算结果表明，该宽带发射源于自陷激子的复合，且发射特性与溴化锡阴离子的几何结构密切相关。研究人员将该材料与商用蓝色荧光粉结合，制备出显色指数达94的高性能紫外泵浦白光发光二极管。