In the past few decades, organic–inorganic hybrid metal halides acting as single-component white light emission diodes (LEDs) have attracted extensive attentions, but most of the studies concentrate on the low-dimensional lead perovskites. Here, by using the nontoxic silver as optically active metal center, a series of hybrid silver halides based on one-dimensional structures were constructed and realized broadband white light emission. Compounds [H2DABCO]­[Ag2X4(DABCO)] (X = Br (1), I (2)) feature one-dimensional [Ag2X4(DABCO)]2– structures charged balanced by [H2DABCO]2+ cations. Compound 1 exhibits an efficient broadband white-light emission with photoluminescence quantum efficiency (PLQE) of about 2.1% and excellent photochemical stability, while compound 2 gives a broadband yellow-white emission centered at 556 nm. [HDABCO]3Ag5Cl8 (3) gives a strong broadband yellow emission (585 nm) with high PLQE of 6.7%, which can be easily fabricated as a white light emitting device. Based on the temperature-dependent, particle-size-dependent, and time-resolved PL measurements as well as other detailed studies, the broadband white-light emissions are ascribed to the synergetic effects of the organic and inorganic components. Our work provides a unique structural assembly method to explore lead-free single-component white-light illuminants from molecular level.

Recently, 2D organic–inorganic hybrid lead halide perovskites have attracted intensive attention in solid‐state luminescence fields such as single‐component white‐light emitters, and rational optimization of the photoluminescence (PL) performance through accurate structural‐design strategies is still significant. Herein, by carefully choosing homologous aliphatic amines as templates, isotypical perovskites [DMEDA]PbCl4 (1, DMEDA=N,N‐dimethylethylenediamine) and [DMPDA]PbCl4 (2, DMPDA=N,N‐dimethyl‐1,3‐diaminopropane) having tunable and stable broadband bluish white emission properties were rationally designed. The subtle regulation of organic cations leads to a higher degree of distortion of the 2D [PbCl4]2− layers and enhanced photoluminescence quantum efficiencies (<1 % for 1 and 4.9 % for 2). The broadband light emissions could be ascribed to self‐trapped excitons on the basis of structural characterization, time‐resolved PL, temperature‐dependent PL emission, and theoretical calculations. This work gives a new guidance to rationally optimize the PL properties of low‐dimensional halide perovskites and affords a platform to probe the structure–property relationship.

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Visible light driven photocatalysts based on crystalline metal halides received much less attention compared with dense or composite oxide semiconductors due to low photochemical stabilities. Here, by using large conjugated organic cations as structural direction agents, a series of hybrid cuprous and/or lead halides have been solvothermally prepared and structurally characterized. Compounds H­[(Me)3-TPT]6(Cu2I6)3(Pb6I19)·(H2O)2 (1) and [(Me)3-TPT]2Cu2Pb3Br14 (2; TPT = 2,4,6-tri­(4-pyridyl)-1,3,5-triazine) contain uncommon Lindqvist-type [Pb6I19]7– nanoclusters and heterometallic [Cu2Pb3Br14]6– units, respectively. Compounds [H3TIB]2Pb5Br16 (3) and H­[(Me)3-TIB]2Pb5I17 (4; TIB = 1,3,5-tris­(1-imidazolyl)­benzene) are composed of one-dimensional (1D) [Pb5Br16]6– chains and two-dimensional (2D) [Pb5I17]7– layers, respectively. The photosensitized conjugated organic cations offer a great contribution to the conduction bands, which lead to narrow band gaps of 2.01–2.35 eV. Under visible light irradiation, compound 4 exhibits efficient and stable photocatalytic degradation activity for various organic pollutants. The possible photocatalytic mechanism obtained from the radical trapping experiments and electronic band structural calculation show that conjugated organic cations effectively inhibit the recombination of photoinduced electron–hole pairs leading to excellent photocatalytic activity and photochemical stability.

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