Metal Halide Research Articles

SnS2-supported MAPbI3 composites for effective photocatalytic hydrogen evolution

Metal halide perovskites have demonstrated encouraging photocatalytic potential due to their favorable photoelectric properties. However, severe carrier recombination greatly affects their catalytic performance. Here, we introduced cocatalyst SnS2 to synthesize novel SnS2/MAPbI3 composites via the electrostatic coupling method, which presented excellent hydrogen production performance. The hydrogen production rate of 5 % SnS2/MAPbI3 (5 wt% SnS2/MAPbI3) reached 445.96 μmol·g−1·h−1, about 325-fold increase compared to pure MAPbI3 (1.37 μmol·g−1·h−1). The 16 h cycle stability test proved its stability and effectiveness. Detailed experimental characterizations and analysis indicate that the cocatalyst SnS2 reduces the surface overpotential and facilitates electron transport and efficiently separates photogenerated charge carriers. This work provides new insights into effective photocatalysts based on MAPbI3.

Microbiome shifts elicited by ornamental lighting of granite facades identified by MinION sequencing

Night-time outdoor illumination in combination with natural sunlight can influence the visible phototrophic colonizers (mainly algae) growing on stone facades; however, the effects on the microbiome (invisible to the naked eye) are not clear. The presence of stone-dwelling microbes, such as bacteria, diatoms, fungi, viruses and archaea, drives further biological colonization, which may exacerbate the biodeterioration of substrates. Considering the microbiome is therefore important for conservation of the built heritage. The impact of the following types of lighting on the relative abundance and diversity of the microbiome on granite ashlars was evaluated in a year-long outdoor pilot study: no lighting; lighting with a metal halide lamp (a traditional lighting system currently used to illuminate monuments); and lighting with a novel LED lamp (an environmentally sound prototype lamp with a biostatic effect, halting biological colonization by phototrophs, currently under trial). Culturable fractions of microbiome and whole-genome sequencing by metabarcoding with Oxford Nanopore Sequencing (MinION) was conducted for bacteria and fungi in order to complement both community characterization strategies. In addition, the possible biodeteriorative profiles of the isolated strains, relative to calcium carbonate precipitation/solubilisation and iron oxidation/reduction, were investigated by plate assays. Alpha and beta diversity indexes were also determined, along with the abundance of biocide and antibiotic resistance genes. Culture-dependent microbiological analysis failed to properly show changes in community composition, for which metagenomic approaches like MinION are better suited. Thus, MinION analysis identified shifts in the granite microbiome elicited by ornamental lighting. The novel LED lamp with the biostatic effect on phototrophs caused an increase in the diversity of bacteria and fungi. In this case, the microbiome was more similar to that in the unlit samples. In the samples illuminated by the metal halide lamp, dominance of bacteria was favoured and the presence of fungi was negligible.

Bromine‐Substituted Cation Anchoring to Suppress Ion Migration in Alternating Cations Intercalation‐Type Perovskite for Stable X‐Ray Detection

Metal halide perovskites have emerged as excellent direct X‐ray detection materials owing to their large mobility‐lifetime product, strong radiation absorption, and low‐cost preparation. However, it is still a challenge to achieve stable X‐ray detection due to the limitations associated with severe ion migration under high voltage bias. Herein, based on a bromine substitution strategy to suppress ion migration, a 2D alternating cations intercalation‐type (ACI) perovskite, (R‐MPA)(BrEA)PbBr4 (1, R‐MPA = methylphenethylamm‐onium; BrEA = 2‐bromoethylamine) is reported to achieve X‐ray detection. Specifically, introducing Br atom forms additional intermolecular interactions (i.e., Br···π) and enhances hydrogen bonding interactions, greatly improving the structure stability. Based on this enhanced interaction, 1 presents a higher activation energy of ion migration (1.05 eV) than that of (R‐MPA)EAPbBr4 resulting in a lower dark current drift of 9.17 × 10−8 nA cm−1 s−1 V−1, revealing that suppression of ion migration. Consequently, the 1‐based detector shows a high sensitivity of 2653.7 μC Gy−1 cm−2 and, most importantly, outstanding operational and environmental stability, maintaining ≈91% of its initial sensitivity at 50 V bias after 90 days in the air. This work demonstrates an efficient strategy for introducing halogen interactions via ACI to suppress ion migration for stable X‐ray detection.

Minimizing Voltage Deficit in Perovskite Indoor Photovoltaics by Interfacial Engineering.

Metal halide perovskites with bandgap of ≈1.8eV are competitive candidates for indoor photovoltaic (IPV) devices, owing to their superior photovoltaic properties and ideal absorption spectra matched to most indoor light sources. However, these perovskite IPVs suffer from severe trap induced non-radiative recombination, resulting in large open-circuit voltage (VOC) losses, particularly under low light intensity. Herein, an effective approach is developed to minimizing trap density by modifying the buried interface of perovskite layer with bifunctional molecular 2-(4-Fluorophenyl)ethylamine Hydrobromide (F-PEABr). The benzene ring of F-PEABr molecules can firmly anchor at the hole transporting layer by π-π stacking interaction, and the other ends can passivate the defects on the buried interface of perovskite layer. Based on that, the F-PEABr modified perovskite IPVs achieved power conversion efficiency (PCE) of 42.3% with a remarkable VOC of 1.13V under 1000 lux illumination from a 4000K LED lamp. Finally, perovskite IPV mini-modules with area of 10.40cm2 are demonstrated with a PCE of 35.2%. This interface modification strategy paves the way for crafting high-performance perovskite IPVs, holding great potential for self-powered internet of things applications.

Enhanced Efficiency and Intrinsic Stability of Wide-Bandgap Perovskite Solar Cells through Dimethylamine-Based Cation Engineering.

High efficiency and stable wide-bandgap perovskite solar cells (PSCs) are important for perovskite-based tandem solar cells. However, the efficiency and stability of wide-bandgap PSCs suffers from severe phase segregation and surface defects. In this study, we propose a cation engineering strategy for wide-bandgap perovskite deposited by a two-stepsequential methodthrough the incorporation ofdimethylamine hydroiodide (DMAI)into the lead halide complex in the first step. The DMAI additive modifies the crystal structure and grain growth of perovskite film, resulting in enhancing crystal quality, suppressing photo-induced halide segregation, reducing defect density, and improving charge carrier mobility. As a result, we achieved a champion photoelectric conversion efficiency (PCE) of 21.9% for 1.68 eV wide-bandgap PSCs. Additionally, the stability of PSCs based on DMA doped perovskite was strongly enhanced, after being exposed to ambient air for 1500 hours, the unencapsulated device maintained an impressive 80.6% of their initial efficiency, demonstrating great potential for stable and efficient wide-bandgap PSCs.

A Strong and Tough Ion‐gel Enabled by Hierarchical Meshing and Ion Hybridizations Collaboration

AbstractIon‐gels, with inherent flexibility, tunable conductivity, and multi‐stimulus response, have attracted significant attention in flexible/wearable electronics. However, the design of ion‐gels that exhibit both strength and toughness is challenging. In this study, a novel ion‐gel design is proposed that mimics the hierarchical meshing structure of leaves in combination with ion hybridization. Polyacrylamide (PAM) is incorporated in TEMPO oxidized cellulose nanofibers (TOCNFs) clusters by in situ polymerization, generating a hydrogel with micro/nanoscale entangled networks. Replacement of water by a metal halide ionic liquid ([BMIm]ZnxCly) in the hydrogel resulted in the formation of an ion hybrid network with supramolecular interactions. The integration of the PAM/TOCNF polymer network with [BMIm]ZnxCly resulted in ion‐gels with high strength (5.9 MPa), toughness (22 MJ m−3), and enhanced elastic modulus (30 MPa) combined with non‐flammability, heat and cold resistance. While having fast responsiveness (36 ms) of sensing signal and stability of power supply even at 4000 cycle collisions. Stable signal output even at high (200 °C) /sub‐zero temperatures. The proposed strategy offers a new approach to the material design of flexible/wearable electronics.

Tunable Blue-Light-Emitting Organic-Inorganic Zinc Halides with Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence.

Hybrid metal halides have received great interests in the field of solid-state lighting technologies due to their diverse structures and excellent emission properties. In this work, we report the synthesis and characterization of four blue-emitting zero-dimensional hybrid metal halides, namely, (2HP)2ZnCl2, (2HP)2ZnBr2, (2TP)2ZnCl2, and (2TP)2ZnBr2 (2HP = 2-hydroxypyridine, 2TP = pyridine-2-thiol). By changing the ligands and halides, a remarkable increase in the photoluminescence quantum yield of (2HP)2ZnCl2 (44.7%) compared to (2TP)2ZnBr2 (1.8%) is realized. The 2HP series features excitation-dependent emission characteristics, whereas the 2TP series does not due to the effect of a different organic ligand. Utilizing time-resolved and temperature-dependent photoluminescence spectroscopies, all four compounds exhibit both thermally activated delayed fluorescence and room-temperature phosphorescence properties. These materials have excellent ambient and thermal stabilities and are solution-processable. Our work shows the importance of carefully incorporating organic ligands with the appropriate inorganic metal center to achieve tunable emission properties.

Mechanistic Interrogation of Photochemical Nickel-Catalyzed Tetrahydrofuran Arylation Leveraging Enantioinduction Data.

This manuscript details the development of an asymmetric variant for the Ni-photoredox α-arylation of tetrahydrofuran (THF), which was originally reported in a racemic fashion by Doyle and Molander. Leveraging the enantioselectivity data that we obtained, a complex mechanistic scenario different from those originally proposed is uncovered. Specifically, an unexpected dependence of the product enantiomeric ratio was observed on both the halide identity (aryl chloride vs bromide substrates) and the Ni source. Stoichiometric experiments and time course analyses of the evolution of product enantioselectivity with time revealed a different initial behavior for reactions carried out with Ni(II) and Ni(0) precatalysts that later converge into a common mechanism. For studying the predominant pathway, this paper describes a rare example of the syntheses of chiral bisoxazoline Ni(II) aryl halide complexes, which proved essential for probing enantioselectivity via stochiometric experiments. These experiments identify the Ni(II) aryl halide complex as the primary species involved in the key THF radical trapping event. A multivariate linear regression model is presented that further validates the dominant mechanism and delineates structure-selectivity relationships between ligand properties and enantioselectivity. EPR analysis of Ni(0)/aryl halide mixtures highlights the fast access to a variety of Ni complexes in 0, +1, and +2 oxidation states that are proposed to be responsible for the initial divergence in mechanism observed when using Ni(0) precatalysts. More broadly, beyond advancing the mechanistic understanding of this THF arylation protocol, this work underscores the potential of leveraging enantioselectivity data to unravel intricate mechanistic manifolds within Ni-photoredox catalysis.

Investigation of Charge Transfer Mechanism and Dielectric Relaxation in CsCdCl3 Perovskite

ABSTRACTThe exceptional optoelectronic capabilities of all‐inorganic metal halide perovskite semiconductor components open up a multitude of possible applications. Among all the metal halides, the chloride of cesium cadmium has not been investigated in great detail. Here, we describe a straightforward method for creating CsCdCl3 perovskite single crystals using the slow evaporation solution growth approach. These were investigated by utilizing X‐ray powder diffraction, and optical and impedance spectroscopies. The creation of a single‐phase with a hexagonal‐type structure was verified by the X‐ray powder diffraction (XRPD) data. The compound's semiconductor characteristics were verified by the optical measurement, indicating a direct band‐gap value of about 3.16 eV. The absorption and reflectance spectrum was also used to calculate and explain the optical extinction coefficient, Urbach energy, and skin depth as functions of the input photon's wavelength. Besides, the impedance spectroscopy technique was employed to investigate the characteristics of this component, across a frequency range of 10−1 Hz to 106 Hz and at temperatures ranging from 313 K to 453 K. The frequency behavior of the AC conductivity, σac, was analyzed using the universal Jonscher law. The outcomes of the charge transport investigation on CsCdCl3 imply that the perovskite material possessed a quantum mechanical tunneling (QMT) model for T < 363 K and a large polaron tunneling (OLPT) paradigm for T > 363 K. A correlation between the ionic conductivity and the crystal structure was established and discussed. Ultimately, the low dielectric loss and high dielectric constant of CsCdCl3 make it a promising material for energy harvesting devices.

Natural and Nature-Inspired Biomaterial Additives for Metal Halide Perovskite Optoelectronics.

This comprehensive review meticulously categorizes and discusses the applications of diverse biomaterials, specifically natural and nature-inspired synthetic materials in metal halide perovskite optoelectronics. Applications range from solar cells to light-emitting diodes, photodetectors, and X-ray detectors. Emphasis is placed on the intricate interactions between bio-additives and perovskite crystals, highlighting their influence on the grain size, crystal orientation, grain boundaries, and surface passivation. This review also explores the advantages and disadvantages of each natural or nature-inspired material and their unique properties compared with conventional additives. Special attention is given to the mechanistic and functional viewpoints, showing how these biomaterials enhance device performance. Through additive engineering with ecofriendly biomaterials, defects in metal halide perovskite thin films can be effectively passivated, thus extending the photostability or in some cases mechanical flexibility of devices. This review provides valuable insights for selecting and designing next-generation biomaterial additives, offering new prospects for achieving high-performance perovskite layers and advancing the field of peorvskite- based optoelectronics.

Oriented Growth of Highly Emissive Manganese Halide Microrods for Dual‐Mode Low‐Loss Optical Waveguides

AbstractZero‐dimensional (0D) structured lead‐free metal halides have recently attracted widespread attention due to their high photoluminescence quantum yield (PLQY) and negligible self‐absorption, showing enormous potential as optical waveguides towards miniaturized photonic devices. However, due to the great difficulty in growth of rod‐like nano/micro‐sized morphologies, such applications have been less explored. Herein, a new‐type emissive organic–inorganic manganese (II) halide crystal (TPS2MnCl4, TPS=C18H15S, triphenylsulfonium) in the form of microrods is synthesized via a facile chloride ion (Cl−) induced oriented growth method. Due to a combination of attractive features such as a high PLQY of 86 %, negligible self‐absorption and smooth crystal surface, TPS2MnCl4 microrods are well suited for use in optical waveguide with an ultra‐low optical loss coefficient of 1.20 ⋅ 10−4 dB μm−1, superior to that of most organic–inorganic metal halide hybrids, organic materials, polymers and metal nanoclusters to the best of our knowledge. Importantly, TPS2MnCl4 microrods can further work as dual‐mode optical waveguides, combining active and passive light transmission functionalities in one single crystal. In addition, TPS2MnCl4 microrods also display remarkable performance in lighting and anti‐counterfeiting due to their distinct optical properties and commendable stability.

Oriented Growth of Highly Emissive Manganese Halide Microrods for Dual-Mode Low-Loss Optical Waveguides.

Zero-dimensional (0D) structured lead-free metal halides have recently attracted widespread attention due to their high photoluminescence quantum yield (PLQY) and negligible self-absorption, showing enormous potential as optical waveguides towards miniaturized photonic devices. However, due to the great difficulty in growth of rod-like nano/micro-sized morphologies, such applications have been less explored. Herein, a new-type emissive organic-inorganic manganese (II) halide crystal (TPS2MnCl4, TPS=C18H15S, triphenylsulfonium) in the form of microrods is synthesized via a facile chloride ion (Cl-) induced oriented growth method. Due to a combination of attractive features such as a high PLQY of 86 %, negligible self-absorption and smooth crystal surface, TPS2MnCl4 microrods are well suited for use in optical waveguide with an ultra-low optical loss coefficient of 1.20 ⋅ 10-4 dB μm-1, superior to that of most organic-inorganic metal halide hybrids, organic materials, polymers and metal nanoclusters to the best of our knowledge. Importantly, TPS2MnCl4 microrods can further work as dual-mode optical waveguides, combining active and passive light transmission functionalities in one single crystal. In addition, TPS2MnCl4 microrods also display remarkable performance in lighting and anti-counterfeiting due to their distinct optical properties and commendable stability.

Enhancement of NIR-II Emission of Er3+ by Doping Fe3+ in Double Perovskites: Multimode Luminescence for Versatile Optoelectronic Applications.

Erbium ions are commonly used to extend the photoelectric properties of metal halide perovskites from visible to near-infrared range. However, achieving high-efficiency multimode luminescence in a single system is difficult due to the weak absorption associated with forbidden 4f-4f transitions. In this study, a unique strategy is proposed to adjust multimode luminescence and enhance the second near-infrared region (NIR-II) emission in Cs2NaBiCl6 by incorporating Fe3+ ions. The as-prepared material demonstrates reversible thermochromism, driven by strong electron-phonon coupling effect, and exhibits tunable luminescence that can be adjusted by altering excitation energy and temperature. Notably, benefitting from the charge transfer transition of Fe3+-Cl- along with the influence of Fe3+ doping on the geometrical and electronic structures, the blue-excitable (450 nm) NIR-II emission around 1541 nm from Er3+ is realized for the first time, achieving an intensity 16.7 times higher and a maximum photoluminescence quantum yield (PLQY) of 22.5 %. This enhancement enables innovative applications such as two-dimensional information encryption by the multi-channel cooperative responses and improved NIR imaging. The study highlights the potential of Fe3+ doping in optimizing absorption and multimode luminescence in perovskites, opening avenues for advanced applications in blue-excitable NIR light emitting diodes (LEDs), thermometer, anti-counterfeiting, and NIR imaging.

Suppressing Energy Migration via Antiparallel Spin Alignment in One‐Dimensional Mn2+ Halide Magnets with High Luminescence Efficiency

AbstractPhotoexcited energy migration is prone to causing luminescence quenching in Mn2+ luminescent materials, presenting a formidable challenge for optoelectronic applications. Although various strategies and mechanisms have been proposed to mitigate this issue, the role of spin alignment between adjacent Mn2+ ions has remained largely unexamined. In this study, we have elucidated the influence of spin alignment on energy migration within the one‐dimensional Mn2+‐metal halide compound (CH3)4NMnCl3 (TMMC) through variable‐temperature photoluminescence (PL) and magnetic‐optical spectroscopy. This investigation was conducted with reference to (CH6N3)2MnCl4 (GUA) with isolated [Mn3Cl12]6− trimers and Cd2+‐doped TMMC. The spin order in TMMC below approximately 55 K is demonstrated by the disorder‐order transition observed in the temperature‐dependent magnetic susceptibility. This finding is further corroborated by the negligible shift in the temperature‐ and field‐dependent emission peaks, a consequence of magnetic saturation. Our results indicate that the antiparallel spin alignment along the Mn2+ chain in TMMC effectively suppresses energy migration and multiphonon relaxation, thereby reducing nonradiative transitions and enhancing the photoluminescence quantum yield (PLQY). This research casts new light on the potential for developing high‐performance Mn2+‐doped phosphors for optoelectronic and spin‐photonic applications, offering insights into the manipulation of spin and energy dynamics in these materials.

Direct Laser Interference Patterning of Fluorine‐Doped Tin Oxide as a Pathway to Higher Efficiency in Perovskite Solar Cells

AbstractImproving light‐trapping capabilities through surface microstructuring of transparent conductive oxides is a promising approach to enhance solar cell efficiency. This study focuses on treating fluorine‐doped tin oxide (FTO) thin films using four‐beam direct laser interference patterning (DLIP) to create dot‐like periodic surface microstructures. The surface analysis using scanning electron microscopy and confocal microscopy reveals the presence of a periodic square grid of microcraters with a spatial period of ≈700 nm and an average depth ranging between 4 and 18 nm. These structures enhance the dispersion of incoming light up to 1000% in the visible and NIR spectra. When integrated into metal halide perovskite solar cells, FTO films patterned using low fluence conditions lead to a notable increase in the power conversion efficiencies (PCEs) compared to those made using untreated FTO. Importantly, preliminary stability tests on devices based on patterned FTO substrates show significantly improved stability compared to those fabricated using reference unpatterned substrates. These findings demonstrate that a DLIP treatment of FTO substrates is a promising technique that can substantially enhance the efficiency and stability of perovskite photovoltaic devices.

Enhancement of NIR‐II Emission of Er3+ by Doping Fe3+ in Double Perovskites: Multimode Luminescence for Versatile Optoelectronic Applications

AbstractErbium ions are commonly used to extend the photoelectric properties of metal halide perovskites from visible to near‐infrared range. However, achieving high‐efficiency multimode luminescence in a single system is difficult due to the weak absorption associated with forbidden 4f‐4f transitions. In this study, a unique strategy is proposed to adjust multimode luminescence and enhance the second near‐infrared region (NIR‐II) emission in Cs2NaBiCl6 by incorporating Fe3+ ions. The as‐prepared material demonstrates reversible thermochromism, driven by strong electron‐phonon coupling effect, and exhibits tunable luminescence that can be adjusted by altering excitation energy and temperature. Notably, benefitting from the charge transfer transition of Fe3+‐Cl− along with the influence of Fe3+ doping on the geometrical and electronic structures, the blue‐excitable (450 nm) NIR‐II emission around 1541 nm from Er3+ is realized for the first time, achieving an intensity 16.7 times higher and a maximum photoluminescence quantum yield (PLQY) of 22.5 %. This enhancement enables innovative applications such as two‐dimensional information encryption by the multi‐channel cooperative responses and improved NIR imaging. The study highlights the potential of Fe3+ doping in optimizing absorption and multimode luminescence in perovskites, opening avenues for advanced applications in blue‐excitable NIR light emitting diodes (LEDs), thermometer, anti‐counterfeiting, and NIR imaging.

Single‐Component White Emissive Organic–Inorganic Hybrid Copper Halide Composite Films for Remote UV‐pumped White Light‐Emitting Diodes with High Color Rendering Index

AbstractLead‐free organic–inorganic metal halides (OIMHs) are highly desirable owing to their remarkable properties including low toxicity, structural diversity, high stability, and solution processability. Nevertheless, the development of their single‐component white emissive films remains a formidable challenge for remote white light‐emitting diodes (WLEDs) application. In this work, (C16H36N)2Cu2I4/polyvinylidene fluoride (PVDF) white emissive composite film is successfully fabricated through an in situ solvent evaporation crystallization process at room temperature. The elemental analysis and bonding between (C16H36N)2Cu2I4 and PVDF are demonstrated by X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) measurements. In addition, this composite film exhibits a broadband white emission with two peaks. Notably, the best photoluminescence quantum yields (PLQYs) of the PVDF based composite film reaches an impressive 96.7%. A (C16H36N)2Cu2I4/PVDF based remote UV‐pumped WLEDs with an impressive color rendering index of 95.5 is realized. Finally, the in situ fabrication method is expanded to fabricate (C16H36N)2Cu2I4/polyacrylonitrile (PAN) composite films, and we further realized their single component remote WLEDs.

Suppressing Energy Migration via Antiparallel Spin Alignment in One-Dimensional Mn2+ Halide Magnets with High Luminescence Efficiency.

Photoexcited energy migration is prone to causing luminescence quenching in Mn2+ luminescent materials, presenting a formidable challenge for optoelectronic applications. Although various strategies and mechanisms have been proposed to mitigate this issue, the role of spin alignment between adjacent Mn2+ ions has remained largely unexamined. In this study, we have elucidated the influence of spin alignment on energy migration within the one-dimensional Mn2+-metal halide compound (CH3)4NMnCl3 (TMMC) through variable-temperature photoluminescence (PL) and magnetic-optical spectroscopy. This investigation was conducted with reference to (CH6N3)2MnCl4 (GUA) with isolated [Mn3Cl12]6- trimers and Cd2+-doped TMMC. The spin order in TMMC below approximately 55 K is demonstrated by the disorder-order transition observed in the temperature-dependent magnetic susceptibility. This finding is further corroborated by the negligible shift in the temperature- and field-dependent emission peaks, a consequence of magnetic saturation. Our results indicate that the antiparallel spin alignment along the Mn2+ chain in TMMC effectively suppresses energy migration and multiphonon relaxation, thereby reducing nonradiative transitions and enhancing the photoluminescence quantum yield (PLQY). This research casts new light on the potential for developing high-performance Mn2+-doped phosphors for optoelectronic and spin-photonic applications, offering insights into the manipulation of spin and energy dynamics in these materials.

Pop the bubbles and let the current flow: mechanochemistry of micron and nano-sized openings in dielectric layers

Thin or ultra-thin dielectric layers have been widely used in various applications such as capacitors, piezo-electrics, and solar cells. This study explains the mechanism and chemistry of creating nano- and micron-sized openings in atomic-layer-deposited aluminum oxide-based dielectric layers using the alkali metal salt selenization technique. The necessary components for this mechanism are excess methyl groups present in the dielectric layer, supply of selenium and alkali metals, and a minimum annealing temperature. It is shown and explained that to create openings in the dielectric layer, heavier alkali halide metal salts require less energy, or - in other words - a lower annealing temperature. The overall hypothesis is explained via a thermodynamic approach with supportive thermochemical reactions. Thus, an easy way to engineer the dielectric layer to form openings at low temperatures is presented, beneficial for various applications like photovoltaics, optoelectronics, or micro-electro-mechanical systems (MEMS).

Tunable double emission of Sb3+/Mn2+ doping stabilized organic-inorganic hybrid zinc-based halides

Low-dimensional organic-inorganic hybrid metal halides (OIHMHs) have attracted much attention lately in contrast to all-inorganic metal halides because of their excellent photophysical properties and tunable emission wavelengths. Zn-based metal halides have the following advantages: simplicity of synthesis, wide bandgap, and excellent chemical stability. Therefore, they are well-suited as host materials for photoluminescence by cation ion doping. We have successfully synthesized intrinsically non-emissive 0D (PPZ)ZnCl4 [PPZ (1-phenylpiperazine) = C10H14N2], and by mono/co-doping with Mn2+ and Sb3+, interesting luminescence phenomena have been produced. Single-doped Mn2+ / Sb3+ shows distinctive green and single orange emission, respectively. However, the co-doped Mn2+ and Sb3+ appeared as dynamic double emission peaks at 530 nm and 670 nm. Therefore, the co-doped crystals showed luminescence from two different luminescence centers ([MnCl4]2- and [SbCl4]-). We used DFT to calculate the DOS (density of states) of co-doped crystals, which results in energy transfer between Mn2+ and Sb3+. All of the above samples showed high stability after being left for two months. In addition, two different luminescence centers can be produced by the adjustment of the excitation of the co-doped (PPZ)ZnCl4: Sb0.12Mn0.08 samples, which is a distinguishable and obvious photoluminescence phenomenon having great potential preparation of advanced anti-counterfeiting materials in the future.