Theoretical insight into physical characteristics of lead-free perovskites Rb2TlSbX6 (X = Cl, Br, I) for optoelectronic devices.

CONTEXT: Novel optoelectronic and thermoelectric properties with broad compositional range, non-toxic nature and structural stability make halide-based double perovskites fascinating for flexible optoelectronic devices. In this work, the structural electronic, optical and transport properties of Rb2TlSbX6 (X = Cl, Br, I) were studied using density functional theory for optoelectronic devices. The elastic analysis demonstrates ductile nature, mechanical stability, anisotropic behaviour and feasibility for flexible optoelectronic devices. The band structure study using Tran-Blaha-modified Becke-Johnson (TB-mBJ) potential shows that all studied materials have direct bandgap. In addition, the bandgap of Rb2TlSbCl6 is more appropriate for optoelectronic devices. The small loss and maximum absorption in visible regions make these materials prime candidates for optoelectronic devices. The transport features indicate that all the studied double perovskites reflect p-type semiconducting behaviour as highlighted by positive Seebeck coefficient values. Furthermore, the high power factor values of Rb2TlSbX6 (X = Cl, Br, I) double perovskites make them suitable for thermoelectric device applications at high temperatures. Based on electronic optical and thermoelectric properties Rb2TlSbCl6 is the best candidate for flexible optoelectronic devices. METHODS: In this paper, structural optimization of Rb2TlSbX6 (X = Cl, Br, I) double perovskites was conducted utilizing the Wien2k software based on first principle calculations with Perdew-Burke-Ernzerhof's generalized-gradient approximation (PBE-sol approximation). The TB-mBJ potential was employed to compute the accurate band gap of studied materials. The thermoelectric properties are evaluated with BoltzTraP code, showing a predominance of P-type charge carriers in all studied perovskites. This methodological strategy verifies the material's remarkable stability and optical properties and offers a solid framework for examining its potential in optoelectronic devices.

Dual Light Emission of CsSnI3-Based Powders Synthesized via a Mechanochemical Process.

Lead toxicity has hindered the wide applications of lead halide perovskites in optoelectronics and bioimaging. A significant amount of effort has been made to synthesize lead-free halide perovskites as alternatives to lead halide perovskites. In this work, we demonstrate the feasibility of synthesizing CsSnI3-based powders mechanochemically with dual light emissions under ambient conditions from CsI and SnI2 powders. The formed CsSnI3-based powders are divided into CsSnI3-dominated powders and CsSnI3-contained powders. Under the excitation of ultraviolet light of 365 nm in wavelength, the CsSnI3-dominated powders emit green light with a wavelength centered at 540 nm, and the CsSnI3-contained powders emit orange light with a wavelength centered at 608 nm. Both the CsSnI3-dominated and CsSnI3-contained powders exhibit infrared emission with the peak emission wavelengths centered at 916 nm and 925 nm, respectively, under a laser of 785 nm in wavelength. From the absorbance spectra, we obtain bandgaps of 2.32 eV and 2.08 eV for the CsSnI3-dominated and CsSnI3-contained powders, respectively. The CsSnI3-contained powders exhibit the characteristics of thermal quenching and photoelectrical response under white light.

Rubidium Doped Cs2AgBiBr6 Hierarchical Microsphere for Enhanced Photocatalytic CO2 Reduction.

Halide perovskites have garnered significant attention for their unique optoelectronic properties in solar-to-fuel conversions. However, the efficiency of halide perovskites in the field of photocatalytic CO2 reduction is largely limited by serious charge recombination and a lack of efficient active sites. In this work, a rubidium (Rb) doped Cs2AgBiBr6 (Rb:CABB) hierarchical microsphere is developed for photocatalytic CO2 reduction. Experimental and theoretical analysis discloses that partially substituting Rb+ for Ag+ can effectively modulate the electronic structure of CABB, favoring charge separation and making adjacent Bi atoms an electron-rich active site. Further investigations indicated that Rb doping also reduces the energy barriers of the rate-determining step in CO2 reduction. As a result, Rb:CABB demonstrated an enhanced CO yield compared to its undoped counterpart. This work presents a promising approach to optimizing the electronic structures of photocatalysts and paving a new way for exploring halide perovskites for photocatalytic CO2 reduction.

A step-scheme-based Cs3Bi2Br9 perovskite quantum dots@mesoporous Nb2O5 photocatalyst with boosted charge separation and CO2 reduction.

Solar-energy-powered CO2 reduction into valuable chemical fuels represents a highly promising strategy to address the currently energy and environmental issues. Owing to the nontoxicity and robust reduction capability, lead-free Cs3Bi2Br9 perovskite quantum dots (PQDs) are regarded as an attractive material for CO2 photoreduction. Nevertheless, the potential of their applications in this field has been restricted by the severe charge recombination, resulting in unsatisfactory photocatalytic performance. Herein, a step-scheme-based Cs3Bi2Br9@Nb2O5 (CBB@Nb2O5) nanocomposite was fabricated by embedding the CBB PQDs into mesoporous Nb2O5. Experimental studies, along with theoretical calculations, revealed that the charge migration route in the CBB@Nb2O5 nanocomposite conformed to the step-scheme (S-scheme) mode, enabling effective charge separation and strong redox ability preservation. Profiting from the promoted charge separation, as well as the improved CO2 adsorption contributed by mesoporous Nb2O5, the CBB@Nb2O5 nanocomposite unveiled superior CO2 photoreduction performance, with CO evolution rate reaching 143.63 µmol g-1h-1. The present study provides a potential strategy to manufacture highly-efficient perovskite-based photocatalysts for achieving carbon neutrality.

Spin-Phonon Coupling in Iron-Doped Ultrathin Bismuth Halide Perovskite Derivatives.

Spin in semiconductors facilitates magnetically controlled optoelectronic and spintronic devices. In metal halide perovskites (MHPs), doping magnetic ions is proven to be a simple and efficient approach to introducing a spin magnetic momentum. In this work, we present a facile metal ion doping protocol through the vapor-phase metal halide insertion reaction to the chemical vapor deposition (CVD)-grown ultrathin Cs3BiBr6 perovskites. The Fe-doped bismuth halide (Fe:CBBr) perovskites demonstrate that the iron spins are successfully incorporated into the lattice, as revealed by the spin-phonon coupling below the critical temperature Tc around 50 K observed through temperature-dependent Raman spectroscopy. Furthermore, the phonons exhibit significant softening under an applied magnetic field, possibly originating from magnetostriction and spin exchange interaction. The spin-phonon coupling in Fe:CBBr potentially provides an efficient way to tune the spin and lattice parameters for halide perovskite-based spintronics.

Machine-Learning-Assisted Discovery of Mechanosynthesized Lead-Free Metal Halide Perovskites for the Oxidative Photocatalytic Cleavage of Alkenes.

Lead-free metal halide perovskites can potentially be air- and water-stable photocatalysts for organic synthesis, but there are limited studies on them for this application. Separately, machine learning (ML), a critical subfield of artificial intelligence, has played a pivotal role in identifying correlations and formulating predictions based on extensive datasets. Herein, an iterative workflow by incorporating high-throughput experimental data with ML to discover new lead-free metal halide perovskite photocatalysts for the aerobic oxidation of styrene is described. Through six rounds of ML optimization guided by SHapley Additive exPlanations (SHAP) analysis, BA2CsAg0.95Na0.05BiBr7 as a photocatalyst that afforded an 80% yield of benzoic acid under the standard conditions is identified, which is a 13-fold improvement compared to the 6% with when using Cs2AgBiBr6 as the initial photocatalyst benchmark that is started. BA2CsAg0.95Na0.05BiBr7 can tolerate various functional groups with 22 styrene derivatives, highlighting the generality of the photocatalytic properties demonstrated. Radical scavenging studies and density functional theory calculations revealed that the formation of the reactive oxygen species superoxide and singlet oxygen in the presence of BA2CsAg0.95Na0.05BiBr7 are critical for photocatalysis.

Superior Phonon-Limited Exciton Mobility in Lead-Free Two-Dimensional Perovskites.

Tin-based two-dimensional (2D) perovskites are emerging as lead-free alternatives in halide perovskite materials, yet their exciton dynamics and transport remain less understood due to defect scattering. Addressing this, we employed temperature-dependent transient photoluminescence (PL) microscopy to investigate intrinsic exciton transport in three structurally analogous Sn- and Pb-based 2D perovskites. Employing conjugated ligands, we synthesized high-quality crystals with enhanced phase stability at various temperatures. Our results revealed phonon-limited exciton transport in Sn perovskites, with diffusion constants increasing from 0.2 cm2 s-1 at room temperature to 0.6 cm2 s-1 at 40 K, and a narrowing PL line width. Notably, Sn-based perovskites exhibited greater exciton mobility than their Pb-based equivalents, which is attributed to lighter effective masses. Thermally activated optical phonon scattering was observed in Sn-based compounds but was absent in Pb-based materials. These findings, supported by molecular dynamics simulations, demonstrate that the phonon scattering mechanism in Sn-based halide perovskites can be distinct from their Pb counterparts.

iso-BAI Guided Surface Recrystallization for Over 14% Tin Halide Perovskite Solar Cells.

Tin-based perovskite solar cells (PSCs) are promising environmentally friendly alternatives to their lead-based counterparts, yet they currently suffer from much lower device performance. Due to variations in the chemical properties of lead (II) and tin (II) ions, similar treatments may yield distinct effects resulting from differences in underlying mechanisms. In this work, a surface treatment on tin-based perovskite is conducted with a commonly employed ligand, iso-butylammonium iodide (iso-BAI). Unlike the passivation effects previously observed in lead-based perovskites, such treatment leads to the recrystallization of the surface, driven by the higher solubility of tin-based perovskite in common solvents. By carefully designing the solvent composition, the perovskite surface is effectively modified while preserving the integrity of the bulk. The treatment led to enhanced surface crystallinity, reduced surface strain and defects, and improved charge transport. Consequently, the best-performing power conversion efficiency of FASnI3 PSCs increases from 11.8% to 14.2%. This work not only distinguishes the mechanism of surface treatments in tin-based perovskites from that of lead-based counterparts, but also underscores the critical role in designing tailor-made strategies for fabricating efficient tin-based PSCs.

An all-inorganic lead-free metal halide double perovskite for the highly selective detection of norfloxacin in aqueous solution.

Lead-based perovskites are highly susceptible to environmental influences, and their application in analytical chemistry, especially in aqueous solution, has been reported rarely. All-inorganic lead-free metal halide perovskites have been considered as a substitute for lead-based perovskites. Herein, a Cs2RbTbCl6 perovskite microcrystal (PMCs), which emits strong yellow-green fluorescence with a maximum emission wavelength at 547 nm, was for the first time  synthesized and characterized. The Cs2RbTbCl6 PMCs could be well dispersed in N,N-dimethylacetamide (DMF), and its fluorescence could be significantly enhanced by the addition of norfloxacin (NOR) in the aqueous solution. We found that the Cs2RbTbCl6 PMCs can be used as fluorescent probes (excitation, 365 nm; emission, 547 nm) to selectively detect NOR in a concentration range from 10.0 to 200.0 µM with the limit of detection (LOD) being 0.04 µM. The Cs2RbTbCl6 PMCs could also be adsorbed on filter paper to fabricate as a fluorescent test paper for visual detection of NOR under 365-nm ultraviolet (UV) lamp irradiation. The proposed method has the potential to establish a new analytical method to visualize the detection of NOR in aqueous environments and also promotes the application of all-inorganic lead-free perovskites for analytical detection in aqueous environments.

Ligand-Induced Chirality in ClMBA2 SnI4 2D Perovskite.

Chiral perovskites possess a huge applicative potential in several areas of optoelectronics and spintronics. The development of novel lead-free perovskites with tunable properties is a key topic of current research. Herein, we report a novel lead-free chiral perovskite, namely (R/S-)ClMBA2 SnI4 (ClMBA=1-(4-chlorophenyl)ethanamine) and the corresponding racemic system. ClMBA2 SnI4 samples exhibit a low band gap (2.12 eV) together with broad emission extending in the red region of the spectrum (∼1.7 eV). Chirality transfer from the organic ligand induces chiroptical activity in the 465-530 nm range. Density functional theory calculations show a Rashba type band splitting for the chiral samples and no band splitting for the racemic isomer. Self-trapped exciton formation is at the origin of the large Stokes shift in the emission. Careful correlation with analogous lead and lead-free 2D chiral perovskites confirms the role of the symmetry-breaking distortions in the inorganic layers associated with the ligands as the source of the observed chiroptical properties providing also preliminary structure-property correlation in 2D chiral perovskites.

Polycrystalline Lead-Free Perovskite Direct X-Ray Detectors with High Durability and Low Limit of Detection via Low-Temperature Coating.

Direct X-ray detectors represent a transformative technology in the realm of radiography and imaging. The double halide-based perovskite cesium silver bismuth bromide (Cs2AgBiBr6) has emerged as a promising material for use in direct X-ray imaging, owing to its nontoxic composition, strong X-ray absorption, decent charge mobility lifetime product (µτ), and low-cost preparation. However, formidable issues related to scalability and ion migration, stemming from intrinsic factors such as halogen vacancies and grain boundaries, have presented significant impediments. These issues have been associated with substantial noise, baseline instability, and a curtailment of detection performance. In response to these multifaceted challenges, we propose a slurry-based in situ treatment technique for fabricating robust Cs2AgBiBr6 thick films. This novel approach adeptly mitigates halogen vacancies, actively passivates grain boundaries, and concurrently elevates the ion migration activation energy, thus effectively suppressing ion migration. Consequently, the obtained X-ray detector exhibits excellent operating stability with minimal signal drift of 8.5 × 10-9 nA cm-1 s-1 V-1 and achieves a remarkable 385% increase in sensitivity with a limit of detection as low as 7.8 nGyair s-1. These results mark a significant step toward the development of high-performance and long-lasting lead-free perovskite direct X-ray detectors.

Efficient and Stable Multicolor Emissions of the Coumarin-Modified Cs3LnCl6 Lead-Free Perovskite Nanocrystals and LED Application.

Lanthanide-based lead-free perovskite materials hold great promise for the development of high-resolution full-color displays in the future. Here, various Cs3LnCl6 perovskite nanocrystals (NCs) emitting light across the visible to near-infrared spectrum with remarkably high photoluminescence quantum yield (PLQY) are systemically prepared. Especially, by introducing multifunctional coumarin small molecules into Cs3EuCl6 NCs as an intermediate state, Cs3EuCl6 NCs can achieve an impressive PLQY of 92.4% with pure red emission and an exceptional energy transfer efficiency of nearly 93.2%. Furthermore, the lanthanide-based electroluminescent devices in red, green, and blue are successfully fabricated. Among them, the Cs3EuCl6-NC-based red light-emitting diode (LED) demonstrates a FWHM of 18 nm at 617 nm, an external quantum efficiency up to 5.17%, and a maximum brightness of 2373 cd m-2, which is the most excellent reported for lead-free narrowband (within 20 nm) emission devices. Notably, these devices exhibit an operating half-life of 440 h at a brightness level of 100 cd m-2, surpassing the performance of most reported lead-free perovskite LEDs (PLEDs). This work opens up exciting possibilities for the future commercialization of lanthanide-based PLEDs in the display industry, paving the way for more vibrant, energy-efficient, and long-lasting display technologies.

Amine Gas-Induced Reversible Optical Bleaching of Bismuth-Based Lead-Free Perovskite Thin Films.

Reversible optical property changes in lead-free perovskites have recently received great interest due to their potential applications in smart windows, sensors, data encryption, and various on-demand devices. However, it is challenging to achieve remarkable color changes in their thin films. Here, methylamine gas (CH3 NH2 , MA0 ) induced switchable optical bleaching of bismuth (Bi)-based perovskite films is demonstrated for the first time. By exposure to an MA0 atmosphere, the color of Cs2 AgBiBr6 (CABB) films changes from yellow to transparent, and the color of Cs3 Bi2 I9 (CBI) films changes from dark red to transparent. More interestingly, the underlying reason is found to be the interactions between MA0 and Bi3+ with the formation of an amorphous liquefied transparent intermediate phase, which is different from that of lead-based perovskite systems. Moreover, the generality of this approach is demonstrated with other amine gases, including ethylamine (C2 H5 NH2 , EA0 ) and butylamine (CH3 (CH2 )3 NH2 , BA0 ), and another compound, Cs3 Sb2 I9 , by observing a similar reversible optical bleaching phenomenon. The potential for the application of CABB and CBI films in switchable smart windows is investigated. This study provides valuable insights into the interactions between amine gases and lead-free perovskites, opening up new possibilities for high-efficiency optoelectronic and stimuli-responsive applications of these emerging Bi-based materials.

Defect Compensation and Lattice Stabilization Enables High Voltage Output in Tin Halide Perovskite Solar Cells.

Tin halide perovskite solar cells (PSCs) are regarded as the most promising lead-free alternatives for photovoltaic applications. However, they still suffer from uncompetitive photovoltaic performance because of the facile Sn2+ oxidation and Sn-related defects. Herein, a defect and carrier management strategy by using diaminopyridine (DP) and 4-bromo-2,6-diaminopyridine (4BrDP) as multifunctional additives for tin halide perovskites is reported. Both DP and 4BrDP induced strong interaction with tin perovskites by coordinate bonding and N─H···I hydrogen bonding, which greatly suppresses the micro-strain and Urbach energy of tin halide perovskite films. The strong hydrogen bonding inhibits the formation of I3 - and related defect density. Meanwhile, the electron-donor species of halogen bond in 4BrDP provides higher reactivity of 2 and 6 sites, which indicates stronger passivation ability with tin halide perovskites. These advances enable a champion power conversion efficiency (PCE) of 13.40% in 4BrDP-processed devices with remarkable improvement in both open-circuit voltage (Voc) of 881 mV and fill factor (FF) of 71.26%. The 4BrDP devices retain 91% and 82% of the pristine PCE after 2000 h storage in N2 atmosphere and 1000 h under 85 °C, respectively. Therefore, this work provides new insight into molecular design for high-performance and stable lead-free optoelectronics.

Recent Advances in Wide Bandgap Perovskite Solar Cells: Focus on Lead-Free Materials for Tandem Structures.

A tandem solar cell, which is composed of a wide bandgap (WBG) top sub-cell and a narrow bandgap (NBG) bottom subcell, harnesses maximum photons in the wide spectral range, resulting in higher efficiency than single-junction solar cells. WBG (>1.6 eV) perovskites are currently being studied a lot based on lead mixed-halide perovskites, and the power conversion efficiency of lead mixed-halide WBG perovskite solar cells (PSCs) reaches 21.1%. Despite the excellent device performance of lead WBG PSCs, their commercialization is hampered by their Pb toxicity and low stability. Hence, lead-free, less toxic WBG perovskite absorbers are needed for constructing lead-free perovskite tandem solar cells. In this review, various strategies for achieving high-efficiency WBG lead-free PSCs are discussed, drawing inspiration from prior research on WBG lead-based PSCs. The existing issues of WBG perovskites such as VOC loss are discussed, and toxicity issues associated with lead-based perovskites are also addressed. Subsequently, the natures of lead-free WBG perovskites are reviewed, and recently emerged strategies to enhance device performance are proposed. Finally, their applications in lead-free all perovskite tandem solar cells are introduced. This review presents helpful guidelines for eco-friendly and high-efficiency lead-free all perovskite tandem solar cells.

Utilizing the Undesirable Oxidation of Lead-Free Hybrid Halide Perovskite Nanosheets for Solar-Driven Photocatalytic C(sp3)─H Activation: Unraveling the Serendipity.

Hybrid halide perovskites (HHPs), whose every branch generates intrusiveness, have been utilized in solar cells from a broader perspective. However, the inclusiveness of employing HHP as a photocatalyst is in its initial stage. This study mainly focuses on the unexpected utilization of, so far, undesirable material vacancy-ordered MA2SnBr6 quantum dots synthesized from MASnBr3 nanosheets. Here, the quantum confinement grounded a large blue shift in ultraviolet (UV) and photoluminescence (PL) spectra with a Stokes shift of 420 meV, where the band gap increase is observed as size decreases in MA2SnBr6. Remarkably, MA2SnBr6 exhibits air and moisture stability, better charge transfer, and high oxidation potential compared to MASnBr3. The first-principles-based atomistic computations reveal the strain relaxation in the Sn-Br framework that structurally stabilizes the MA2SnBr6 lattice. Furthermore, the direct band gap and strongly localized valence band edge give rise to a new potential photocatalyst MA2SnBr6 for efficient solar-driven C(sp3)─H activation of cyclohexane and toluene under ambient conditions.

Interfacial B-Site Ion Diffusion in All-Inorganic Core/Shell Perovskite Nanocrystals.

All-inorganic metal halide perovskites (ABX3, X = Cl, Br, or I) show great potential for the fabrication of optoelectronic devices, but the toxicity and instability of lead-based perovskites limit their applications. Shell passivation with a more stable lead-free perovskite is a promising strategy to isolate unstable components from the environment as well as a feasible way to tune the optical properties. However, it is challenging to grow core/shell perovskite nanocrystals (NCs) due to the soft ionic nature of the perovskite lattice. In this work, we developed a facile method to grow a lead-free CsMnCl3 shell on the surface of CsPbCl3 NCs to form CsPbCl3/CsMnCl3 core/shell NCs with enhanced environmental stability and improved photoluminescence (PL) quantum yields (QYs). More importantly, the resulting core/shell perovskite NCs have color-tunable PL due to B-site ion diffusion at the interface of the core/shell NCs. Specifically, B-site Mn diffusion from the CsMnCl3 shell to the CsPbCl3 core leads to a Mn-doped CsPbCl3 core (i.e., Mn:CsPbCl3), which can turn on the Mn PL at around 600 nm. The ratio of Mn PL and host CsPbCl3 PL is highly tunable as a function of the thermal annealing time of the CsPbCl3/CsMnCl3 core/shell NCs. While the halide anion exchange for all-inorganic metal halide perovskites has been well-developed for band-gap-engineered materials, interfacial B-site diffusion in core/shell perovskite NCs is a promising approach for both tunable optical properties and enhanced environmental stability.

Regulating Exciton De-Trapping of Te4+ -Doped Zero-Dimensional Scandium-Halide Perovskite for Fluorescence Thermometry with Record High Time-Resolved Thermal Sensitivity.

Fluorescence thermometry has been propelled to the forefront of scientific attention due to its high spatial resolution and remote non-invasive detection. However, recent generations of thermometers still suffer from limited thermal sensitivity (Sr ) below 10% change per Kelvin. Herein, this work presents an ideal temperature-responsive fluorescence material through Te4+ -doped 0D Cs2 ScCl5 ·H2 O, in which isolated polyhedrons endow highly localized electronic structures, and the strong electron-phonon coupling facilitates the formation of self-trapped excitons (STEs). With rising temperature, the dramatic asymmetric expansion of the soft lattice induces increased defects, strong exciton-phonon coupling, and low thermal activation energy, which evokes a rapid de-trapping process of STEs, enabling several orders of magnitude changes in the fluorescence lifetime over a narrow temperature range. After regulating the de-trapping process with different Te4+ doping, a record-high Sr (27.36% K-1 ) of fluorescence lifetime-based detection is achieved at 325 K. The robust stability against multiple heating/cooling cycles and long-term measurements enables a low temperature uncertainty of 0.067 K. Further, the developed thermometers are demonstrated for the remote local monitoring of operating temperature on internal electronic components. It is believed that this work constitutes a solid step towards building the next generation of ultrasensitive thermometers based on low-dimensional metal halides.

Lead-Free Perovskite Thin Films with Tailored Pockels-Kerr Effects for Photonics.

Pockels and Kerr effects are linear and nonlinear electro-optical effects, respectively, used in many applications. The modulation of the refractive index is employed in different photonic circuits. However, the greatest challenge is in photonic elements for quantum computing at room temperature. For this aim, materials with strong Pockels/Kerr effects and χ(2)/χ(3) nonlinear susceptibilities are necessary. Here, we demonstrate composition-modulated strong electro-optical response in epitaxial films of (Ba,Ca)(Ti,Zr)O3 perovskite titanate. These films are grown by pulsed laser deposition on SrTiO3. Depending on the ratios of Ca/Ba and Ti/Zr, films show high Pockels or Kerr optical nonlinearities. We relate the variable electro-optic response to the occurrence of nanopolar domains with different symmetries in a selected composition range. These findings open the route to easily implement nonlinear optical elements in integrated photonic circuits.

Ferroelectric Modulation in Flexible Lead-Free Perovskite Schottky Direct-Current Nanogenerator for Capsule-Like Magnetic Suspension Sensor.

The tribovoltaic nanogenerator (TVNG), a promising semiconductor energy technology, displays outstanding advantages such as low matching impedance and continuous direct-current output. However, the lack of controllable and stable performance modulation strategies is still a major bottleneck that impedes further practical applications of TVNG. Herein, by leveraging the ferroelectricity-enhanced mechanism and the control of interfacial energy band bending, a lead-free perovskite-based (3,3-difluorocyclobutylammonium)2 CuCl4 ((DF-CBA)2 CuCl4 )/Al Schottky junction TVNG is constructed. The multiaxial ferroelectricity of (DF-CBA)2 CuCl4 enables an excellent surface charge modulating capacity, realizing a high work function regulation of ≈0.7 eV and over 15-fold current regulation (from 6 to 93 µA) via an electrical poling control. The controllable electrical poling leads to elevated work function difference between the Al electrode and (DF-CBA)2 CuCl4 compared to traditional semiconductors and halide perovskites, which creates a stronger built-in electric field at the Schottky interface to enhance the electrical output. This TVNG device exhibits outstanding flexibility and long-term stability (>20 000 cycles) that can endure extreme mechanical deformations, and can also be used in a capsule-like magnetic suspension device capable of detecting vibration and weights of different objects as well as harvesting energy from human motions and water waves.