In-Plane Bulk Photovoltaic Effect in a MoSe/NbOI Heterojunction for Efficient Polarization-Sensitive Self-Powered Photodetection.

Two-dimensional ferroelectric materials can generate a bulk photovoltaic effect, making them highly promising for self-powered photodetectors. However, their practical application is limited by a weak photoresponse due to a weak transition strength and wide band gap. In this study, we construct a van der Waals heterojunction using NbOI, which has significant in-plane polarization, with a highly absorbing MoSe layer.

Glass Disorder Modulated Luminescence in Zero-Dimensional Antimony-Chloride Coplanar Dimers for Optical Anti-counterfeiting.

Zero-dimensional metal halides have received wide attention due to their structural diversity, strong quantum confinement, and associated excellent photoluminescence properties. A reversible and tunable luminescence would be desirable for applications such as anti-counterfeiting, information encryption, and artificial intelligence. Yet, these materials are underexplored, with little known about their luminescence tuning mechanisms.

The luminescent properties of metal halides are determined by the inorganic framework and solvent molecules.

The luminescent properties of metal halides are usually considered to be determined by the inorganic framework. In this work, we propose that the luminescent properties of metal halides are determined by both the inorganic framework and the solvent [Denoted as (inorganic framework + n·solvent molecules), n = 0, 1, 2…] through the abundant solvatochromic or thermochromic effect of tetrabutylammonium lead bromides [TPB, T = TBA (tetrabutylammonium), P = Pb (lead), B = Br (bromide)] containing water (HO) and ethanol (EtOH). One-dimensional (1D) TPB can form ligands of [[PbBr] + 2HO], [[PbBr] + 2HO + 2HO] and [[PbBr] + 2EtOH] by solvent or heat treatment has completely different luminescent properties resulting from different solvents.

Structural Transformation and Photoluminescent Property of Manganese-Doped Bismuth-Based Perovskites.

Here, we synthesized pure CsBiCl (CBC) and manganese (Mn)-doped crystals with different feeding ratios, leading to changes in structure and luminescence. The crystals CsBiCl-Mn (CBCM) formed by doping a minor amount of Mn (Bi/Mn = 8:1) maintain the orthorhombic phase structure of the host, but when Bi/Mn = 2:1, the crystal structure is more inclined to form CsMnBiCl (CMBC) of a trigonal phase. Combined with density functional theory (DFT) calculation, the results demonstrate that a moderate amount of Mn doping can create impurity energy levels in the forbidden band.

Photophysical properties of tetrabutylammonium metal chlorides with different inorganic frameworks.

The luminescence of single crystals of (TBA)PbCl, (TBA)SbCl, (TBA)BiCl and (TBA)SnCl·2EtOH (TBA = tetrabutylammonium, EtOH = Ethanol) synthsized were assigned distinctively to the centres of self-trapped excitons (STEs), TBA, TBA and co-emission of STEs and TBA. This work demonstrates that organic cations without benzene or aromatic rings can also be used as the sole luminescence centres for metal halides.

Highly Sensitive Dual-Mode Optical Thermometry of Er/Yb Codoped Lead-Free Double Perovskite Microcrystal.

In this Letter, erbium (Er) and ytterbium (Yb) codoped perovskite CsAgNaInBiCl microcrystal (MC) is synthesized and demonstrated systematically to the most prospective optical temperature sensing materials. A dual-mode thermometry based on fluorescence intensity ratio and fluorescence lifetime provides a self-reference and highly sensitive temperature measurement under dual wavelength excitation at a temperature from 300 to 470 K. Combined with the white-light emission derived from self-trapped excitons (STEs), the characteristic emission peak of Er ions can be observed under 405 nm laser excitation.