Lead-containing Materials Research Articles

Interface Engineering of Lead-Free Perovskite Quantum Dots for High-Performance Data Encryption and Ultralow UV-Light Detection

Recently discovered lead-free perovskite quantum dots (QDs) have been touted as a new non-toxic star material that will replace lead-containing perovskite materials. However, its potential applications have not been advanced due to their high density of defect states. On the other hand, it is almost impossible to precisely control the luminescence of organic chromophores from different excited states with different emission colors. Here, we addressed these two great challenges in a single experiment by expanding the utility of lead-free perovskite materials capped with luminescence chromophores into brand new research directions and light-harvesting application. More specifically, we have successfully promoted the use of lead-free perovskite QDs as an efficient and reversible switch for chromophore luminescence for sensitive UV-light detection, with an extremely low detection limit of 74 picoW/cm2 and high-performance data encryption. Our time-resolved absorption and luminescence experiments, and density functional theory calculations have clearly demonstrated that ultrafast electron transfer from the optical excited Cs3MBi2Cl9 perovskite QDs tune and control the nature of neighboring organic chromophore luminescence, leading to different emission colors from different electronic excited states. This variation in interface color in response to different excitation energies provides a feasible strategy for high-performance information anti-counterfeiting and the ultralow detection limit of ultraviolet light.

Thermodynamic optimization of the Cu–As–S system

A literature review, critical assessment and thermodynamic modeling of matte, metal (speiss) and solid phases in the Cu–As–S system are presented. The literature data include enthalpies and entropies of formation, activity measurements using vapor pressure, phase equilibrium and element distribution data. The model for the liquid phase was developed within the framework of the Modified Quasichemical Model (MQM) in pair approximation. Liquid metal and matte phases were described using the single solution with a miscibility gap. Previously published model parameters for the liquid phase in the Cu–S system were modified to achieve agreement with the data for the Cu–As–S system. The resulting set of model parameters was incorporated into a large multicomponent thermodynamic database intended for predictions of phase equilibria, heat balance and distribution of arsenic in the course of pyrometallurgical processing of copper- and lead-containing materials.

Novel 1–3 (K,Na)NbO3-based ceramic/epoxy composites with large thickness-mode electromechanical coupling coefficient and good temperature stability

The 1–3 piezoelectric composites are an important type of artificial functional materials for ultrasonic transducers. Currently, there are increasingly strong demands to replace the lead-containing materials. Excellent 1–3 0.96(K0.48Na0.52) (Nb0.96Sb0.04)O3−0.03BaZrO3−0.01(Bi0.50Na0.50)ZrO3 ceramic/epoxy (abbreviated hereafter as KNNS-0.03BZ-0.01BNZ/epoxy) piezoelectric composites were prepared by a modified dice-and-fill technique. Compared to the monolithic KNNS-0.03BZ-0.01BNZ ceramic, the developed composites possess much larger electromechanical coupling coefficient kt of 0.54–0.67 and piezoelectric voltage coefficient g33 of 64–91 × 10−3 Vm/N. In addition, these composites also possess other favorable properties such as low values of acoustic impedance Z of 6.9–13.4 Mrayl, dielectric coefficient ε33 of 130–400 and mechanical quality factor Qm of 1.3–4. More importantly, kt is weakly temperature-dependence in the common usage temperature range between −30 °C and 100 °C. The result indicates that the 1–3 KNNS-0.03BZ-0.01BNZ/epoxy piezoelectric composites have a great potential for high-frequency ultrasonic transducers.

Ferrate(VI) pretreatment of water containing natural organic matter, bromide, and iodide: A potential strategy to control soluble lead release from PbO2(s)

Lead dioxide (PbO2(s)) is a corrosion product of lead-containing plumbing materials in water distribution pipelines. The presence of reductants in water could cause the release of soluble lead (mainly Pb(II)) from PbO2(s). Lead in drinking water is detrimental to public health. This paper presents the first application of ferrate (FeVIO42−, Fe(VI)) to decreasing the generation of soluble lead in water containing PbO2(s) and common reducing constituents (e.g., natural organic matter (NOM), iodide (I−), and bromide (Br−)) at different pH conditions (i.e., 6.0, 7.0, and 8.0). The released soluble lead from PbO2(s) was found to be dominantly controlled by NOM in water, via the redox dissolution of PbO2(s) and the reduction of PbO2(s) by reducing moieties of NOM. The feasibility of both processes increased when pH decreased. The I− and Br− in water played minor roles in generating soluble lead. Fe(VI) reacted with reducing functional groups of NOM, as determined by 13C nuclear magnetic resonance spectroscopy. Water pretreatment with Fe(VI) inhibited the reaction of NOM with PbO2(s) and therefore, caused lower soluble lead concentrations compared to water samples without Fe(VI) treatment. This study indicates that Fe(VI) pretreatment is a potential approach to controlling soluble lead in drinking water.

Ultrahigh field-induced strain in lead-free ceramics

Abstract Due to the worldwide concerns of environmental protection and sustainable development, lead-free piezoelectric materials are greatly desired for bridging the electrical energy to the mechanical energy. However, their lower energy conversion coefficient compared to the conventional lead-containing piezoelectric materials significantly limits their device applications. Herein, we introduce a novel strategy to increase the strain of lead-free ferroelectric system via material structure design to create polar nano regions (PNRs) and point defects in the material while retaining the global ferroelectric phase. This added short-range structural heterogeneity in the material will facilitate the field-induced phase transition and reversible domain wall switching to enhance the strain. Following this strategy, we demonstrate an ultrahigh strain induced by an electric field in non-textured lead-free Bi0.5Na0.5TiO3 (BNT)-based ceramics. The strain in unipolar mode (Suni) can reach up to 0.74% at 70 kV/cm, making it the highest value in reported lead-free ceramics so far. This puts forward a good route to design high-performance piezoelectric materials by material structure engineering. It also reveals the promising potential of lead-free piezoelectric materials in practical electromechanical device applications.

Phase Evolution in Methylammonium Tin Halide Perovskites with Variable Temperature Solid-State 119Sn NMR Spectroscopy

Hybrid organic–inorganic metal-halide perovskite materials are an emerging class of materials that could profoundly change the optoelectronic and solar absorber research fields and have far-reaching applications. Unfortunately, the leading solar-absorbing candidates are lead-containing materials and suffer from chemical instability, eventually decomposing, resulting in detrimental long-term environmental concerns. A series of nontoxic group 14 Sn(II)-based hybrid organic–inorganic metal-halide perovskites is investigated using variable-temperature solid-state nuclear magnetic resonance (NMR) spectroscopy to examine their unique phases that appear between 150 and 540 K. Each phase of the MASnX3 (MA+ = CH3NH3+ and X– = Cl–, Br–, or I–) series is identified and compared to results from quantum chemical calculations of anionic polyhedron clusters. The analysis of the polyhedra about the Sn center is further related to the measured chemical shift anisotropy present when Sn deviates from octahedral symmetry. We also discuss the rapid degradation of pristine MASnI3 over 2 days studied using in situ 119Sn NMR spectroscopy. Finally, we report on the 1H, 13C, 119Sn, and 207Pb NMR structural properties of a Sn/Pb mixed B-site (MASn0.5Pb0.5I3) perovskite, demonstrating the sensitivity of the chemical shift to B-site substitution.

The complex structural mechanisms behind strain curves in bismuth sodium titanate–barium titanate

In this work, the lead-free composition (1-x)Bi0.5Na0.5TiO3–xBaTiO3 (BNT–BT) with x = 0.12 was investigated using in situ Synchrotron x-ray powder diffraction. With the applied electric field, the pseudo-cubic relaxor phase reversibly transforms to a ferroelectric state. The reversibility is still preserved after 104 bipolar electric field cycles. A Rietveld refinement with a structure, strain, and texture analysis using a model based on the atomic scale was applied for four frequencies from 10−4 to 101 Hz. The analysis allowed us to separately determine the two coexisting phases, their electric field dependent evolution, and the underlying strain mechanisms. For all the applied frequencies, we showed that domain switching is the only strain mechanism appearing in the tetragonal phase and the lattice strain is the only mechanism in the rhombohedral phase. The coercive field of the tetragonal phase (4 kV/mm) is found to be higher than that of the rhombohedral phase (3 kV/mm). This divergence has not been observed in previously investigated lead-containing materials and cannot be detected solely using macroscopic strain and polarization experiments. Moreover, the domain strain abruptly starts to occur only after a threshold field value and exhibits high hysteresis. The lattice strain, on the other hand, starts nearly from the beginning and increases more linearly during the bipolar field cycle. It could, therefore, be demonstrated that complex structural mechanisms underlie the apparent clear and continuous macroscopic strain curve. These findings are crucial for all actuator materials undergoing a relaxor to ferroelectric phase transformation and provide approaches and strategies to optimize lead-free materials for tailored applications.

A Large Piezoelectric Strain Recorded in BCT Ceramics Obtained by a Modified Pechini Method.

There is a strong need in the industry to develop lead-free piezoelectrics for sensors and actuators. Although these materials have become an important component of many electronic devices, it is very important for the industry to decarbonise ceramic technology, especially through the introduction of modern sintering technologies. Among the many piezoelectric compounds available, Calcium Barium Titanate (BCT) have been widely investigated because of its similar performance to lead-containing Lead Titanate Zirconate (PZT). In this paper, a modified Pechini method for obtaining ceramic Ba0.9Ca0.1TiO3 nano-powders is described. Deviation from the established procedure resulted in the precipitation of the solution or obtaining of a low-quality (poorly crystallized) product with numerous impurities. The samples of BCT materials were examined to find their ideal microstructures and structures; these factors were confirmed by their outstanding X-ray diffraction spectra and high piezoelectric constant values that are comparable to commercial lead-containing materials.

The solubility of Cu, Pb, As, Sb of copper-lead matte in the slag

An installation was developed and studies were carried out to determine the oxide solubility of copper, lead, arsenic, and antimony from copper-lead matte to slag under conditions of controlled values ​​of РО2=2,74*10-4 Pa and PS2=1,45*102 Pa, applicable to smelting reduction processes of copper-, lead-containing raw materials. It was found that the oxide solubility of copper from matte to slag increases monotonously with an increase of copper content in the matte. The presence of lead in the matte does not significantly affect the final solubility of copper in the slag. In a reducing atmosphere, the solubility of copper in slag is 0.28-0.35%, at the range of copper content of 30-45% in the matte, which is typical for industrial practice. The solubility of lead from copper-lead matte to slag has higher values ​​and increases to 1%. According to the results of mineralogical studies, there is no metallic form of arsenic in slags. Arsenic in slags was found in the form of oxide (As2O5) bound to silicate. Antimony in slag was found in oxide and metallic form. Moreover, the proportion of the last form in the slag prevails. It is shown that under reduction conditions the sublimation of arsenic and antimony from copper-lead matte is difficult. Equilibrium concentrations of As, Sb in the slag (0.17%) are achieved with their optimum content in the matte which is about 0.63%. Obtained results can be used to predict the loss of oxide solubility of copper and to develop optimal solutions to reduce the total loss of copper with slag during the reduction processes of separate processing of copper-, lead containing raw materials.

Inorganic Halide Double Perovskites with Optoelectronic Properties Modulated by Sublattice Mixing.

All-inorganic halide double perovskites have emerged as a promising class of materials that are potentially more stable and less toxic than lead-containing hybrid organic-inorganic perovskite optoelectronic materials. In this work, 311 cesium chloride double perovskites (Cs2BB'Cl6) were selected from a set of 903 compounds as likely being stable on the basis of a statistically learned tolerance factor (τ) for perovskite stability. First-principles calculations on these 311 double perovskites were then performed to assess their stability and identify candidates with band gaps appropriate for optoelectronic applications. We predict that 261 of the 311 Cs2BB'Cl6 compounds are likely synthesizable on the basis of a thermodynamic analysis of their decomposition to competing compounds (decomposition enthalpy <0.05 eV/atom). Of these 261 likely synthesizable compounds, 47 contain no toxic elements and have direct or nearly direct (within 100 meV) band gaps between 1 and 3 eV, as computed with hybrid density functional theory (HSE06). Within this set, we identify the triple-alkali perovskites Cs2[Alk]+[TM]3+Cl6, where Alk is a group 1 alkali cation and TM is a transition-metal cation, as a class of Cs2BB'Cl6 double perovskites with remarkable optical properties, including large and tunable exciton binding energies as computed by the GW-Bethe-Salpeter equation (GW-BSE) method. We attribute the unusual electronic structure of these compounds to the mixing of the Alk-Cl and TM-Cl sublattices, leading to materials with small band gaps, large exciton binding energies, and absorption spectra that are strongly influenced by the identity of the transition metal. The role of the double-perovskite structure in enabling these unique properties is probed through an analysis of the electronic structures and chemical bonding of these compounds in comparison with other transition-metal and alkali transition-metal halides.

Interphase Distribution of Elements during Two-Stage High Temperature Electrochemical Treatment of Lead-Bismuth Alloys

Experimental simulation of the separation of the components of lead-bismuth alloy in a chloride melt is conducted. Using X-ray fluorescence, emission spectral and X-ray powder diffraction analyses, the interphase distribution of elements is estimated during high-temperature (550 С) electrochemical treatment of lead-bismuth alloys in molten NaCl–KCl–PbCl2 –ZnCl2 . Regimes of the two-stage process are substantiated when in the first stage (U = 7.4–15.6 V, ia = 0.5 A/cm2 ) the bismuth content in anode alloy is brought to 48.4 wt.% and then (U = 4.9-13.5 V, ia = 0.3-0.4 A/cm2 ) crude bismuth is separated containing, wt.%: 93.6 Bi, 4.1 Pb, 0.086 Ag, 0.0066 As, 0.006 Sb, 0.0013 Cu, 0.001 Sn, and 0.0014 Zn. The final anode product contains 93% bismuth and 0.4% lead from the original alloy. Crude lead obtained at the cathode contains, wt.%: 95.8–96.3 Pb, 0.007–0.06 Bi, 0.002–2.9 Na, 1.2–3.6 Zn, and ≤ 0.1 Cu. Sublimation of chlorides saturated with lead and action of oxygen from the air are the reasons for heterogenization of the electrolyte that gives rise to an increase in working voltage in the electrolytic cell. The relatively low anodic and cathodic current efficiency (50 and 38% respectively) are associated with electrical recharging of polyvalent ions on electrodes. Use of technology for treating intermediate products and waste refining will make it possible to organize production of crude bismuth from mineral and secondary lead-containing raw materials. Prospects for improving the efficiency of the process are associated with the sealing of electrolyzers and preliminary pyrometallurgical refining of lead-bismuth alloys from impurities (Cu, Zn, Sb, As, and Sn).

Light-Enhanced Spin Diffusion in Hybrid Perovskite Thin Films and Single Crystals.

Organolead trihalide perovskites have attracted substantial interest with regard to applications in charge-based photovoltaic and optoelectronic devices because of their low processing costs and remarkable light absorption and charge transport properties. Although spin is an intrinsic quantum descriptor of a particle and spintronics has been a central research theme in condensed matter physics, few studies have explored the spin degree of freedom in the emerging hybrid perovskites. Here, we report the characterization of a spin valve that uses hybrid perovskite films as the spin-transporting medium between two ferromagnetic electrodes. Because of the light-responsive nature of the hybrid perovskite, a high magnetoresistance of 97% and a large spin-diffusion length of 81 nm were achieved at 10 K under light illumination in polycrystalline films. Furthermore, by using thin perovskite single crystals, we discovered that the spin-diffusion length was able to reach 1 μm at low temperatures. Our results indicate that the spin relaxation is not significant as previously expected in such lead-containing materials and demonstrate the potential of low-temperature-processed hybrid perovskites as new active materials in spintronic devices.

Lead toxicosis in cats and dogs

Lead has no biological role but is ubiquitous in the environment. The incidence of lead poisoning in both humans and animals has declined in the past few decades; however, there are still potential sources in and around the home, including lead paint and lead-containing materials such as curtain weights and lead flashing. Signs of lead poisoning mainly involve the gastrointestinal and neurological systems, and a typical presentation is several days’ history of gastrointestinal signs (anorexia, vomiting) followed by neurological signs such as seizures. Behavioural changes may also be reported. Diagnosis of lead poisoning can be difficult, since a blood lead concentration is not immediately available and does not correlate well with severity of poisoning. Diagnosis is therefore usually based on clinical signs, laboratory findings and client history. Treatment is aimed at identifying the source of poisoning, reducing/eliminating exposure, management of signs, and potential use of a lead chelating agent. Prognosis is good with treatment, but more guarded in animals with severe neurological signs.

Formation and Aggregation of Lead Phosphate Particles: Implications for Lead Immobilization in Water Supply Systems.

Phosphate is commonly added to drinking water to inhibit lead release from lead service lines and lead-containing materials in premise plumbing. Phosphate addition promotes the formation of lead phosphate particles, and their aggregation behaviors may affect their transport in pipes. Here, lead phosphate formation and aggregation were studied under varied aqueous conditions typical of water supply systems. Under high aqueous PO4/Pb molar ratios (>1), phosphate adsorption made the particles more negatively charged. Therefore, enhanced stability of lead phosphate particles was observed, suggesting that although addition of excess phosphate can lower the dissolved lead concentrations in tap water, it may increase concentrations of particulate lead. Adsorption of divalent cations (Ca2+ and Mg2+) onto lead phosphate particles neutralized their negative surface charges and promoted their aggregation at pH 7, indicating that phosphate addition for lead immobilization may be more efficient in harder waters. The presence of natural organic matter (NOM, ≥ 0.05 mg C/L humic acid and ≥ 0.5 mg C/L fulvic acid) retarded particle aggregation at pH 7. Consequently, removal of organic carbon during water treatment to lower the formation of disinfection-byproducts (DBPs) may have the additional benefit of minimizing the mobility of lead-containing particles. This study provided insight into fundamental mechanisms controlling lead phosphate aggregation. Such understanding is helpful to understand the observed trends of total lead in water after phosphate addition in both field and pilot-scale lead pipe studies. Also, it can help optimize lead immobilization by better controlling the water chemistry during phosphate addition.

Properties of lead-free gamma-ray shielding materials from metal oxide/EPDM rubber composites

This work investigated the gamma-ray shielding, cure characteristics, physical, and mechanical properties of ethylene propylene diene monomer (EPDM) rubber composites with additions of metal oxides (either iron (II, III) oxide; Fe3O4, tungsten (III) oxide; W2O3 or bismuth (III) oxide; Bi2O3) for potential use as flexible, durable, and lead-free gamma-ray shielding materials. The results showed that increases in the metal oxide contents from 0 to 100, 300, and 500 phr (parts per hundred of rubber), respectively, improved the gamma-ray shielding properties of the EPDM rubber composites with the highest gamma attenuation in 500-phr Bi2O3. The results also showed initial decreases in the cure times at a 100-phr metal oxide content but subsequently increased at higher contents (300 phr and 500 phr). Furthermore, while tensile modulus at 100% elongation and hardness (Shore A) kept increasing with increasing metal oxide contents, tensile strength and elongation at break behaved differently as they initially increased at 100 phr but later decreased at 300 phr and 500 phr. In addition, after the accelerated-weathering studies, the tensile modulus at 100% elongation and tensile strength of the EPDM rubber composites increased but the elongation at break and hardness (Shore A) decreased. In summary, the overall properties suggested that these developed metal oxide/EPDM rubber composites could be effectively used to replace lead-containing materials as durable gamma-ray shielding materials.

Shock-driven depolarization behavior in BNT-based lead-free ceramics

The pulsed power supply that generates megawatts of electrical power has drawn important attention for many decades. Despite that the large energy output has been obtained in lead-containing materials such as Pb(Zr0.95Ti0.05)O3 (PZT95/5) ceramics, lead-free ferroelectric candidates are highly desired due to the environmental concerns. In this work, we report the depolarization behavior of lead-free ternary 0.99[0.98(Bi0.5Na0.5)(Ti0.995Mn0.005)O3-0.02BiAlO3]-0.01NaNbO3 ferroelectric ceramics under shock wave compression. A current profile with a maximum value of ∼25 A and a FWHM of ∼2.3 μs was obtained. Particularly, the poled BNT-BA-0.01NN ceramics were almost completely depolarized under high strain rate loading, releasing a high charge density J of 38 μC/cm2. The released J was approximately 96% of thermal-induced charge density (∼40 μC/cm2), which was 18% higher than that of PZT95/5 ceramics. The shock-induced depolarization mechanism can be attributed to the ferroelectric-ergodic relaxor phase transition. These results reveal the BNT-based ceramics as promising candidates for pulsed power applications.

Anisotropy Factors and Electromechanical Coupling in Lead-Free 1-3-Type Composites.

The effective electromechanical properties and anisotropy factors of novel lead-free 1-3-type composites are studied to demonstrate their large piezoelectric anisotropy and considerable level of electromechanical coupling. The composites studied contain two single-crystal (SC) components and a polymer component. The first piezoactive component is a domain-engineered [001]-poled SC based on ferroelectric alkali niobates-tantalates, and this component is in the form of a system of long rods that are parallel to the poling axis . The second SC component is a system of spheroidal piezoelectric Li2B4O7 inclusions aligned in a continuous and relatively large polymer matrix. The SC rods are surrounded by an SC/polymer matrix, and the connectivity of the composite is 1-0-3. It is shown that the conditions , which indicates a large degree of anisotropy of the piezoelectric coefficients, and and , which indicate a large anisotropy of the electromechanical coupling factors (ECFs), can be achieved simultaneously in specific ranges of the component volume fractions and inclusion aspect ratios. Moreover, in the same volume-fraction and aspect-ratio ranges, large ECFs ( -0.9) are also achieved. In this context, the important role of the elastic properties of the continuous anisotropic matrix is discussed. The properties and anisotropy factors of the lead-free 1-3-type composites are compared to the similar parameters of conventional lead-containing piezoelectric materials, and the advantages of the composite system studied are described.

Designing Stability into Thermally Reactive Plumbylenes

Lead analogues of N-heterocyclic carbenes (NHPbs) are the least understood members of this increasingly important class of compounds. Here we report the design, preparation, isolation, structure, volatility, and decomposition pathways of a novel aliphatic NHPb: rac- N 2, N 3-di- tert-butylbutane-2,3-diamido lead(II) (1Pb). The large steric bulk of the tert-butylamido moieties and rac-butane backbone successfully hinder redox decomposition pathways observed for diamidoethylene and -ethane backbone analogues, pushing the onset of thermal decomposition from below 0 °C to above 150 °C. With an exceptionally high vapor pressure of 1 Torr at 94 ± 2 °C and excellent thermal stability among Pb(II) complexes, 1Pb is a promising precursor for the chemical vapor deposition (CVD) and atomic layer deposition (ALD) of functional lead-containing materials.

Distribution of Corrosion Potentials across Galvanically Coupled Interfaces Exposed in Drinking Water

Control of lead release from lead-containing materials galvanically coupled with copper or bronze represent a challenge for corrosion engineers and water treatment practitioners. Currently available data show that in some situations galvanically coupled lead remains passivated and releases little metal while in other cases, for instance those associated with changes of ambient water chemistry, previously passive coupled lead becomes active with resultant episodes of elevated lead release. While this problem has been thoroughly investigated on a phenomenological level, current understanding of the electrochemistry of galvanic stimulation of lead corrosion and release in drinking water remains insufficient. The goal of this study was to quantify changes of the open circuit corrosion potential (Ecorr(x)) across lead/copper interfaces as a function of the distance from the galvanic juncture and concentrations of background salts such sodium chloride, carbonate and others. The theory developed by Song et al. 2010 provides a detailed mathematical description of the distribution of Ecorr across galvanic interfaces but this theory has been developed and rested for systems that are notably different from those typical for drinking water. Measurements of trans-galvanic interface Ecorr profiles performed in this study showed that Ecorr(x) profiles conformed to predictions made based on the existing theory and the effective length of the longitudinal penetration of ionic currents increased as a square root of solution conductivity. The effective length of the coupled ionic currents was notably different for copper and lead. The data demonstrate that short- and long-term changes of properties of ambient water can cause Ecorr(x) to undergo considerable changes. This can potentially induce shifts of the galvanically affected zone in which accelerated lead release takes place. Further studies are needed to examine actual effects of such Ecorr(x) shifts on spatially localized lead release from galvanically coupled lead-containing materials. Song, G. L. (2010). Potential and current distributions of one-dimensional galvanic corrosion systems. Corrosion Science, 52(2), 455-480

Copper-Substituted Lead Perovskite Materials Constructed with Different Halides for Working (CH3NH3)2CuX4-Based Perovskite Solar Cells from Experimental and Theoretical View

Toxicity and chemical instability issues of halide perovskites based on organic-inorganic lead-containing materials still remain as the main drawbacks for perovskite solar cells (PSCs). Herein, we discuss the preparation of copper (Cu)-based hybrid materials, where we replace lead (Pb) with nontoxic Cu metal for lead-free PSCs, and investigate their potential toward solar cell applications based on experimental and theoretical studies. The formation of (CH3NH3)2CuX4 [(CH3NH3)2CuCl4, (CH3NH3)2CuCl2I2, and (CH3NH3)2CuCl2Br2] was discussed in details. Furthermore, it was found that chlorine (Cl-) in the structure is critical for the stabilization of the formed compounds. Cu-based perovskite-like materials showed attractive absorbance features extended to the near-infrared range, with appropriate band gaps. Green photoluminescence of these materials was obtained because of Cu+ ions. The power conversion efficiency was measured experimentally and estimated theoretically for different architectures of solar cell devices.