Lead-free copper-based halide hybrid materials have emerged as a class of potential candidates for next-generation optoelectronic devices. In this work, we demonstrated that Gua4Cu4Br8 and Gua3Cu2I5 (Gua = CH6N3+) single...

Light-emitting diodes (LEDs) with the circularly polarized luminescence features have attracted attention to the promising applications ranging from solid-state lighting and displays to bioencoding and anticounterfeiting. The prerequisite of circularly polarized luminescence is highly emissive chiral materials. Here, we demonstrated that (R/S-MBA) 4 Cu 4 I 8 •2H 2 O (MBA = α-methylbenzylaminium) and acentric Gua 6 Cu 4 I 10 (Gua = guanidinium) single crystals were grown on the basis of Gua 3 Cu 2 I 5 by the slow evaporation method. (R/S-MBA) 4 Cu 4 I 8 •2H 2 O single crystals exhibited excellent circularly polarized luminescence (CPL) characteristics. More importantly, ultraviolet-pumped LEDs (UV-LEDs) based on (R/S-MBA) 4 Cu 4 I 8 •2H 2 O and Gua 6 Cu 4 I 10 single crystals exhibit a higher optical selectivity when exposed to right-handed and left-handed circular polarization (RCP and LCP) conditions. (S-MBA) 4 Cu 4 I 8 •2H 2 O single crystals and Gua 6 Cu 4 I 10 single crystals induced by the (R)-MBA cation exhibit the different polarized light intensities at PL peak positions in different λ/4 waveplate polarizer angle directions, which provides new possibilities for the further applications from 3D displays to spintronics, as well as anticounterfeiting.

Organic–inorganic hybrid copper(I)‐based halides have attracted great interest in the field of optoelectronics due to their low cost, non‐toxicity, large Stokes shift, and high photoluminescence quantum yields (PLQYs). Here, bulk zero‐dimensional (0D) organic‐inorganic hybrid copper(I)‐based (R,S‐2‐mpip)2Cu2I6 (mpip = methylpiperazinium, C5H14N22+) single crystals have been grown with equal stoichiometric ratios of R‐ and S‐2‐mpip ligands by chirality–racemization strategy for the first time. Interestingly, (R,S‐2‐mpip)2Cu2I6 single crystals exhibit strong blue–green photoluminescence (PL) located at 520 nm with large Stokes shift of about 230 nm and high PLQY of about 65.96%, which originates from self‐trapped excitons (STEs). More importantly, (R,S‐2‐mpip)2Cu2I6 single crystals also exhibit the strong radioluminescence (RL) at 520 nm, the fast X‐ray scintillation response with a light yield of about 47 000 photon MeV−1 and low detection limit of 6.48 nGyairs−1 when exposed to X‐ray irradiation condition, which is superior to that of other copper(I) iodide‐based hybrids. Based on the excellent characteristics, X‐ray imaging systems based on (R,S‐2‐mpip)2Cu2I6 single crystals exhibit the clear images of “QFNU” logo and crystal symbol pattern. This work not only deepens the understandings of material design and fundamental properties of these racemate systems, but also provides guidance for the further applications in the multi‐functional optoelectronics.

Phase transformations of tin halide hybrid materials have played an important role in the formations of structural diversity and optoelectronic versatility due to the oxidability and instability from Sn2+ to...

Lead (Pb)-free halide hybrid materials have received a great deal of attention because of their potential in optoelectronic applications. However, heteroatom-based amine lead-free tin halide hybrid single crystals have not been well investigated yet. Detailed synthetic processes, growth, crystal structures, and stability of (ACH 2 CH 2 NH 3 ) 2 SnBr 6 (A = OH or SH) and (BCH 2 CH 2 NH 3 ) 2 SnI 4 (B = I or SH) single crystals were investigated. Interestingly, (IH 3 NCH 2 CH 2 SSCH 2 CH 2 NH 3 ) 2 HPO 3 exhibited orange-red photoluminescence (PL) at about 620 nm w i t h a n a v e r a g e P L l i f e t i m e o f a b o u t 9 1 2 n s . (HSCH 2 CH 2 NH 3 ) 2 SnI 4 single crystals exhibited a PL peak at 620 nm with an average PL lifetime of about 0.607 ns. More importantly, (HSCH 2 CH 2 NH 3 ) 2 SnI 4 single crystals exhibited reversible red−black color transformations when exposed to a H 3 PO 2 solution and an ambient atmosphere, which was attributed to oxidation from Sn 2+ to Sn 4+ , rather than from I − to I 3 − (I 2 ). The intriguing characteristics should provide guidance for further optoelectronic applications of these Pb-free halide hybrid materials.