Ultrastable, cationic three-dimensional lead bromide frameworks that intrinsically emit broadband white-light

Abstract

We have discovered the first two lead halide materials adopting a purely cationic inorganic 3D topology. The highly distorted PbII centers afford strong electron–phonon coupling in a deformable lattice and unusual broadband white-light emission as an intrinsic property.

White light emission in low-dimensional perovskites

“…71 In this regard, the main observations include: i) Emission bandwidth and PLQY are unrelated to the perovskite crystal size remaining substantially unchanged in films, powders and nanocrystals, excluding the involvement of surface/edge states in the emission process. 8,70,72 ii) The integrated PL intensity of broadband emission linearly increases with the excitation intensity over several orders of magnitude without showing saturation, ruling out the contribution of permanent defects (particularly in Cl and Br perovskites). 8,62,63,67 iii) The PL temperature dependence is consistent with the presence of an energy barrier for the selftrapping process, which is expected given the structural rearrangement necessary to induce charge localization.…”

Intrinsic White‐Light‐Emitting Metal–Organic Frameworks with Structurally Deformable Secondary Building Units

“…Recently, broadband white‐light emission as an intrinsic property has been realized in ⟨110⟩‐oriented corrugated 2D or 1D organolead halide perovskites, which is attributed to the formation of self‐trapped excitons . This promising class of white‐light emitters is amenable to crystal engineering for further enhancing their photoluminescence properties . However, the intrinsic moisture instability of lead perovskites has not been fully addressed …”

Intrinsic White‐Light‐Emitting Metal–Organic Frameworks with Structurally Deformable Secondary Building Units

“…[6][7][8][9][10][11][12] This promising class of white-light emitters is amenable to crystal engineering for further enhancing their photoluminescence properties. [13][14][15][16][17][18] However,the intrinsic moisture instability of lead perovskites has not been fully addressed. [19] Luminescent metal-organic frameworks (MOFs) are considered to be an ideal platform for single-phase white-light photoemitters,o wing to their capability to organize multiple photoemissive components into as ingle lattice.…”