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.