Stable white photoluminescence from Mn-contained organic lead bromide perovskite ring arrays formed from 2D colloidal crystal templates

Abstract

Metal halide perovskites have proven to be reliable white light-emitting materials from a single component. Ordered metal halide perovskite arrays have drawn much attention because of their applications in lasing and displays. However, perovskite arrays capable of emitting white light are still underresearched. Herein, a C₄N₂H₁₄Pb_xMn_1−xBr₄ perovskite ring array based on a feasible and simple 2D colloidal crystal template is reported. By optimizing the molar feed ratio (C₄N₂H₁₄Br₂/PbBr₂/MnBr₂ is 4/3/1), bright white emission has been achieved, which originates from both C₄N₂H₁₄PbBr₄ and the Mn dopant. The diameters of perovskite rings can be tuned continuously from 2.5 μm to 6.2 μm by simply preprocessing the template as confirmed by observing the changes in the contact area between the annealed template and the substrate as well as the drying process of the perovskite precursor. Compared with perovskite thin films without a template, the perovskite ring array has better stability in humid environments. By coating an ultraviolet light-emitting diode (LED) chip with a C₄N₂H₁₄Pb_xMn_1−xBr₄ ring array film, we fabricated white LEDs which showed high color quality with CIE color coordinates of (0.32, 0.32), a color rendering index of 85, and a correlated color temperature of 5645 K.