Inhomogeneous Charge Distribution Research Articles

Regulation on photocatalytic debromination by the reconfiguration of carbonyl groups on the covalent organic frameworks

Covalent organic frameworks (COFs) as promising organic semiconductor photocatalysts have become a research hotspot in the field of photocatalytic organic synthesis. Herein, a series of imine-linked EN-COF-x were synthesized by condensation reaction of amine monomer with triformylbenzene monomer. Then, β-ketoamine-linked KE-COF-y were obtained by the reconstruction of EN-COF-x in alkaline solution. The photocatalytic performance of COFs before and after the isomerization from enols to ketones were investigated. The characterization results and density functional theory calculations clearly demonstrated that the carbonyl groups not only make the conduction band energy level more negative, but also lead to a more inhomogeneous charge distribution in the molecule, which improved the separation efficiency of the photogenerated electrons. In addition, the increase in the number of hydroxyl groups on triformylbenzene monomer contributed to the formation of more carbonyl groups in the COF frameworks, which is beneficial to improving its photocatalytic performance. KE-COF-3 synthesized from 2,4,6-Trihydroxy-1,3,5-benzenetricarbaldehyde has more carbonyl group units and more suitable redox potential, which effectively promoted the debromination reaction with 99% yield under light irradiation. Meanwhile, it can be reused at least five times without loss of catalytic activity. This work provides insights for the rational design of functionalized β-ketoamine COFs for photocatalytic organic transformations.

Facile Lithium Densification Kinetics by Hyperporous/Hybrid Conductor for High-Energy-Density Lithium Metal Batteries.

Lithium metal anode (LMA) emerges as a promising candidate for lithium (Li)-based battery chemistries with high-energy-density. However, inhomogeneous charge distribution from the unbalanced ion/electron transport causes dendritic Li deposition, leading to "dead Li" and parasitic reactions, particularly at high Li utilization ratios (low negative/positive ratios in full cells). Herein, an innovative LMA structural model deploying a hyperporous/hybrid conductive architecture is proposed on single-walled carbon nanotube film (HCA/C), fabricated through a nonsolvent induced phase separation process. This design integrates ionic polymers with conductive carbon, offering a substantial improvement over traditional metal current collectors by reducing the weight of LMA and enabling high-energy-density batteries. The HCA/C promotes uniform lithium deposition even under rapid charging (up to 5mA cm-2) owing to its efficient mixed ion/electron conduction pathways. Thus, the HCA/C demonstrates stable cycling for 200 cycles with a low negative/positive ratio of 1.0 when paired with a LiNi0.8Co0.1Mn0.1O2 cathode (areal capacity of 5.0mAhcm-2). Furthermore, a stacked pouch-type full cell using HCA/C realizes a high energy density of 344Whkg-1 cell/951WhL-1 cell based on the total mass of the cell, exceeding previously reported pouch-type full cells. This work paves the way for LMA development in high-energy-density Li metal batteries.

Tidal Mixed Ionic/Electronic Conductive Interlayer Enables Supersmooth Lithium Deposition for Stable Lithium Metal Batteries

AbstractLithium metal is the ultimate anode material for Li‐based battery chemistries with high energy density. However, inhomogeneous charge distribution derived from the unbalanced ion/electron transport is usually generated at the electrode/electrolyte interface, leading to uncontrollable dendrite growth with poor reversibility. Herein, a mixed ionic/electronic conductive (MIEC) interlayer activated from the in situ conversion and nano‐alloying reactions between the sputtered AlN arrays and metallic Li is efficiently constructed on the Li surface via facile mechanical calendaring. The 3D interconnected polyimide scaffolds with the extensive Li3N/Li9Al4 dual‐decoration promote charge redistribution while enhancing electrochemical kinetics. The significantly reduced nucleation/plateau overpotentials, the overwhelming bottom‐up lithium growth pattern derived from the tidal MIEC interlayer, combined with the inorganics‐dominating solid electrolyte interphase synergistically regulates the uniform Li nucleation/growth. As demonstrated, a prolonged lifespan of the symmetric cell over 7500 h with an ultralow polarization of 12 mV is achieved at 5 mA cm−2@5 mAh cm−2, further improving the rate capability and cycling performance of LiFePO4‐based practical full cells with a capacity retention of 85.4% after 220 cycles. The proposed approach is also applicable to match the roll‐to‐roll production process, presenting an efficient strategy to realize the high‐performance composite anode of industry‐adaptable potential.

The Keto‐Switched Photocatalysis of Reconstructed Covalent Organic Frameworks for Efficient Hydrogen Evolution

AbstractThe keto‐switched photocatalysis of covalent organic frameworks (COFs) for efficient H2 evolution was reported for the first time by engineering, at a molecular level, the local structure and component of the skeletal building blocks. A series of imine‐linked BT‐COFs were synthesized by the Schiff‐base reaction of 1, 3, 5‐benzenetrialdehyde with diamines to demonstrate the structural reconstruction of enol to keto configurations by alkaline catalysis. The keto groups of the skeletal building blocks served as active injectors, where hot π‐electrons were provided to Pt nanoparticles (NPs) across a polyvinylpyrrolidone (PVP) insulting layer. The characterization results, together with density functional theory calculations, indicated clearly that the formation of keto‐injectors not only made the conduction band level more negative, but also led to an inhomogeneous charge distribution in the donor‐acceptor molecular building blocks to form a strong intramolecular built‐in electric field. As a result, visible‐light photocatalysis of TP‐COFs‐1 with one keto group in the skeletal building blocks was successfully enabled and achieved an impressive H2 evolution rate as high as 0.96 mmol g−1 h−1. Also, the photocatalytic H2 evolution rates of the reconstructed BT‐COFs‐2 and ‐3 with two and three keto‐injectors were significantly enhanced by alkaline post‐treatment.

Regulating single-atom Mn sites by precisely axial pyridinic-nitrogen coordination to stabilize the oxygen reduction

Designing single-atom catalysts for oxygen reduction reaction (ORR) are fashionable but challenging to boost the zinc-air battery performance. Significantly enhanced ORR activity by manganese (Mn) single-atom catalysts can be achieved by accurately regulating the coordination number of isolated Mn atoms. Theoretical calculations indicate that the single Mn-N5 sites possess lower free energy barrier and higher oxygen adsorption performance than single Mn-N4 sites to accelerate the ORR kinetics. Target to it, here we synthesize an atomically dispersed Mn-N5 catalyst by precisely axial coordination of pyridinic-N doped into two-dimensional (2D) porous nanocarbon sheets (∼3.56 nm thickness), which reveals outstanding catalytic activity and ultrahigh stability for the ORR in zinc-air battery owing to the inhomogeneous charge distribution of Mn-N5 sites compared to the conventional single-site Mn-N4 catalyst and Pt/C. This work gives a new strategy for in situ regulating the electronic structure of metal single-atoms and further promoting the overall ORR performance in energy systems.

Unveiling the capabilities of bipolar conical channels in neuromorphic iontronics.

Conical channels filled with an aqueous electrolyte have been proposed as promising candidates for iontronic neuromorphic circuits. This is facilitated by a novel analytical model for the internal channel dynamics [Kamsma et al., 2023, arXiv:2301.06158], the relative ease of fabrication of conical channels, and the wide range of achievable memory retention times by varying the channel lengths. In this work, we demonstrate that the analytical model for conical channels can be generalized to channels with an inhomogeneous surface charge distribution, which we predict to exhibit significantly stronger current rectification and more pronounced memristive properties in the case of bipolar channels, i.e. channels where the tip and base carry a surface charge of opposite sign. Additionally, we show that the use of bipolar conical channels in a previously proposed iontronic circuit features hallmarks of neuronal communication, such as all-or-none action potentials and spike train generation. Bipolar channels allow, however, for circuit parameters in the range of their biological analogues, and exhibit membrane potentials that match well with biological mammalian action potentials, further supporting their potential biocompatibility.

Streamer dynamics and periodical discharge regime transitions under repetitive nanosecond pulses with airflow

Although the nanosecond repetitively pulsed (NRP) discharge normally stabilizes into one of three regimes (corona/glow/spark) in a pulse train, another nonintuitive instability recently proved that it could periodically swing between corona and spark regimes characterized by repeated spark quenches and reestablishments (Zhao et al 2022 Plasma Sources Sci. Technol. 31 045005). In this paper, we have further investigated the suitability of NRP discharge regime transitions for different pulsed power supplies and revealed dramatic effects of the gas flow on streamer dynamics that possibly lead to spark quenches. Pulse-sequence and temporally resolved electrical and optical diagnostics were implemented to capture discharge evolutions in long pulse trains. Periodical discharge regime transitions under long-term repetitive nanosecond pulses are prevalent under a transmission line transformer pulser and a commercially available FID pulser with parameter constraints. A minimum deposited energy per spark is required for the successive spark pattern. The spark channel before its quench statistically prefers to deviate upstream rather than following the straight axis or intuitively bending downstream to search for more remnants. Before spark quenches, the initial streamer already either exhibits a large radial ‘detour’ or propagates with a zig-zag profile along the periphery of previous spark regions. The periodical discharge regime transition and effects of the gas flow are qualitatively explained based on the plasma–source coupling, evolutions of dominant negative ion composition, and 3D streamer simulation. Periodical NRP spark quenches are probably initiated with the streamer ‘detour’ and then accelerated by the thermal-ionization feedback instability. Inhomogeneous residual charge distribution and accumulations of complex negative ions with high electron bound energies may facilitate the following discharge to search for the gas inlet. In-depth understanding of NRP discharge instabilities could be reached, which are fundamentally governed by residual charge transport and energy relaxation.

Noncoordinating Secondary Sphere Ion Modulates Supramolecular Clustering of Lanthanides

The role of counterions in molecular recognition of lanthanides is underexplored, especially when they exhibit weak interactions with the metal cations. Here, we report a complementary and comprehensive investigation integrating theoretical calculations with X-ray absorption fine structure spectroscopy, dynamic light scattering, and small-angle X-ray scattering to reveal atomic-scale structural features beyond the immediate coordination sphere of a system used for rare-earth element separations. Our results indicate the formation of an unusual T-shaped outer-sphere lanthanide complex, containing two ligands and two nitrate ions in the first coordination sphere, whereas the third nitrate is weakly coordinated and resides in the second shell. This unique structural arrangement causes inhomogeneous charge distribution, leading to self-assembly of the complexes into larger nanoclusters through sterically directed electrostatic interactions in the nonpolar medium. Our findings point to the importance of "noncoordinating" anions in defining the degree of supramolecular aggregation and ion cluster assembly.

High output performance flutter-driven triboelectric nanogenerator

A key challenge that limits the actual application of flutter-driven triboelectric nanogenerators is the low electrical output. In this work, by deeply studying the vibrating process of flutter-driven triboelectric nanogenerator, we found that the inhomogeneous triboelectric charge distribution on the two face-to-face vibrating films and the inconsistent separation distance between different parts of these two films during vibrating process jointly lead to different driving effects of different parts of the films on the free electrons flowing in the external circuit, which are even opposite, thereby resulting in the low output of the flutter-driven triboelectric nanogenerators. To effectively avoid the cancellation and increase the output performance, the large area vibrating films are rationally separated into several parts with relative homogeneous triboelectric charge distribution and consistent separation distance with opposite film during vibrating process by the method of electrode segmentation and integration, which effectively makes the low output flutter-driven triboelectric nanogenerator into a high output contact-separated triboelectric nanogenerator composed of several integratable output units. By further optimization, the new developed flutter-driven TENG has the transferred charge density per time of 22.25 mC s−1 m−2, which is 2.8 times the record value (7.95 mC s−1 m−2), and 14 times of the value 1.57 mC s−1 m−2 of the general traditional structure flutter-driven TENG with the same area. It can light 2792 LEDs under a gentle wind (3.3 m s−1), which is 2.25 times of the maximum number (1240) reported in previous works under much stronger wind with speed of 15 m s−1.

Closing the loop between microstructure and charge transport in conjugated polymers by combining microscopy and simulation

A grand challenge in materials science is to identify the impact of molecular composition and structure across a range of length scales on macroscopic properties. We demonstrate a unified experimental-theoretical framework that coordinates experimental measurements of mesoscale structure with molecular-level physical modeling to bridge multiple scales of physical behavior. Here we apply this framework to understand charge transport in a semiconducting polymer. Spatially-resolved nanodiffraction in a transmission electron microscope is combined with a self-consistent framework of the polymer chain statistics to yield a detailed picture of the polymer microstructure ranging from the molecular to device relevant scale. Using these data as inputs for charge transport calculations, the combined multiscale approach highlights the underrepresented role of defects in existing transport models. Short-range transport is shown to be more chaotic than is often pictured, with the drift velocity accounting for a small portion of overall charge motion. Local transport is sensitive to the alignment and geometry of polymer chains. At longer length scales, large domains and gradual grain boundaries funnel charges preferentially to certain regions, creating inhomogeneous charge distributions. While alignment generally improves mobility, these funneling effects negatively impact mobility. The microstructure is modified in silico to explore possible design rules, showing chain stiffness and alignment to be beneficial while local homogeneity has no positive effect. This combined approach creates a flexible and extensible pipeline for analyzing multiscale functional properties and a general strategy for extending the accesible length scales of experimental and theoretical probes by harnessing their combined strengths.

Revealing the Mechanism of sp-N Doping in Graphdiyne for Developing Site-Defined Metal-Free Catalysts.

Due to the limited reserves of metals, scientists are devoted to exploring high-performance metal-free catalysts based on carbon materials to solve environment-related issues. Doping would build up inhomogeneous charge distribution on surface, which is an efficient approach for boosting the catalytic performance. However, doping sites are difficult to control in traditional carbon materials, thus hindering their development. Taking the advantage of unique sp-C in graphdiyne (GDY), a new N doping configuration of sp-hybridized nitrogen (sp-N), bringing a Pt-comparable catalytic activity in oxygen reduction reaction is site-defined introduced. However, the reaction intermediate of this process is never captured, hindering the understanding of the mechanism and the precise synthesis of metal-free catalysts. After the four-year study, the fabrication of intermediate-like molecule is realized, and finally sp-N doped GDY via the pericyclic reaction is obtained. Compared with GDY doped with other N configurations, the designed sp-N GDY shows much higher catalytic activity in electroreduction of CO2 toward CH4 production, owing to the unique electronic structure introduced by sp-N, which is more favorable in stabilizing the intermediate. Thus, besides opening the black-box for the site-defined doping, this work reveals the relationship between doping configuration and products of CO2 reduction.

Charge Distribution and Spin Textures in Magic-Angle Twisted Bilayer Graphene

The spin density wave existing on the background of the inhomogeneous charge distribution is examined as a possible ground state of the magic-angle twisted bilayer graphene. When interactions are not included, the spectrum of the material has four (eight if spin is taken into account) almost flat almost degenerate bands. Interactions break down the degeneracy forming an order parameter which is usually assumed to be a spin density wave with a preset spin structure. Here, a possible charge density wave contribution to the order parameter; i.e., an inhomogeneous distribution of the charge density within a twisted graphene supercell is taken into account. The spin structure of the order parameter is calculated self-consistently. It is found that the density wave order is stable in the whole doping range from –4 to +4 extra electrons per supercell. The spin texture changes from collinear at zero doping to almost coplanar at finite doping. The density wave order shows nematic distortion when we dope the system. It is demonstrated that the local spin magnetization in energy units is much stronger than the charge density variation, unless doping exceeds three extra electrons or holes per supercell.

Ferroelastic Zr2P2XY (X/Y = I, Br, Cl or F; X [formula omitted] Y) monolayers with tunable in-plane electronic anisotropy and remarkable out-of-plane piezoelectricity

Two-dimensional materials with ferroelasticity, directional control of electronic behaviors and strong piezoelectricity are highly desirable for developing advanced multifunctional nanodevices. Here, we report the new tetragonal Zr2P2XY (X/Y = I, Br, Cl or F; X ≠ Y) monolayers with intrinsic ferroelasticity and remarkable piezoelectricity, based on first-principles calculation. These novel monolayers with semiconductor properties are dynamically, thermally and mechanically stable. The promising anisotropic properties of both mechanics and electron can be perpendicularly controlled based on the intrinsic ferroelasticity. Moderate switching barriers and reversible ferroelastic strains demonstrate their excellent ferroelastic performances along in-plane direction. Additionally, the inhomogeneous charge distribution caused by mirror asymmetry endows these monolayers with strong out-of-plane piezoelectricity. The remarkable piezoelectric strain coefficient d33 = 129.705 pm/V found in Zr2P2BrCl monolayer is two orders of magnitude higher than that of MoSTe multilayer. The Zr2P2BrCl monolayer has such excellent ferroelasticity, controllable anisotropic electronic properties along in-plane directions, and strong piezoelectricity along out-of-plane direction. It provides a unique platform for memory devices, robot bionic skin, or multipurpose nanodevices that require the special electronic and piezoelectric properties along different directions at same time.

Highly aligned lithiophilic electrospun nanofiber membrane for the multiscale suppression of Li dendrite growth

Using inorganic fibrous membranes as protective layers has yielded success in suppressing dendrite growth. However, conventional fibrous membranes usually have large voids and low affinity for Li, promoting inhomogeneous charge distribution and allowing some dendrites to grow. Herein, we introduce a highly aligned TiO2/SiO2 (A-TS) electrospun nanofiber membrane as a protective layer for the Li metal anode. The A-TS membrane is fabricated by a custom-made electrospinning system with an automatic fiber alignment collector that allows control of the fibers’ orientation. At the scale of the individual fibers, their high binding energies with Li can attract more “dead” Li by reacting with the SiO2 component of the composite, avoiding uncontrollable deposition on the metal anode. At the membrane scale, these highly ordered structures achieve homogeneous contact and charge distribution on the Li metal surface, leaving no vulnerable areas to nucleate dendrite formation. Additionally, the excellent mechanical and thermal stability properties of the A-TS membrane prevent any potential puncturing by dendrites or thermal runaway in a battery. Hence, an A-TS@Li anode exhibits stable cycling performance when used in both Li–S and Li–NCM811 batteries, highlighting significant reference values for the future design and development of high-energy-density metal-based battery systems.

Manipulating Interactions between Dielectric Particles with Electric Fields: A General Electrostatic Many-Body Framework.

We derive a rigorous analytical formalism and propose a numerical method for the quantitative evaluation of the electrostatic interactions between dielectric particles in an external electric field. This formalism also allows for inhomogeneous charge distributions, and, in particular, for the presence of pointlike charges on the particle surface. The theory is based on a boundary integral equation framework and yields analytical expressions for the interaction energy and net forces that can be computed in linear scaling cost, with respect to the number of interacting particles. We include numerical results that validate the proposed method and show the limitations of the fixed dipole approximation at small separation between interacting particles. The proposed method is also applied to study the stability and melting of ionic colloidal crystals in an external electric field.

Metal-Support Interaction and Charge Distribution in Ceria-Supported Au Particles Exposed to CO.

Understanding how reaction conditions affect metal–support interactions in catalytic materials is one of the most challenging tasks in heterogeneous catalysis research. Metal nanoparticles and their supports often undergo changes in structure and oxidation state when exposed to reactants, hindering a straightforward understanding of the structure–activity relations using only ex situ or ultrahigh vacuum techniques. Overcoming these limitations, we explored the metal–support interaction between gold nanoparticles and ceria supports in ultrahigh vacuum and after exposure to CO. A combination of in situ methods (on powder and model Au/CeO2 samples) and theoretical calculations was applied to investigate the gold/ceria interface and its reactivity toward CO exposure. X-ray photoelectron spectroscopy measurements rationalized by first-principles calculations reveal a distinctly inhomogeneous charge distribution, with Au+ atoms in contact with the ceria substrate and neutral Au0 atoms at the surface of the Au nanoparticles. Exposure to CO partially reduces the ceria substrate, leading to electron transfer to the supported Au nanoparticles. Transferred electrons can delocalize among the neutral Au atoms of the particle or contribute to forming inert Auδ− atoms near oxygen vacancies at the ceria surface. This charge redistribution is consistent with the evolution of the vibrational frequencies of CO adsorbed on Au particles obtained using diffuse reflectance infrared Fourier transform spectroscopy.

An Air-Rechargeable Zn/Organic Battery with Proton Storage.

Air-rechargeable zinc batteries are a promising candidate for self-powered battery systems since air is ubiquitous and cost-free. However, they are still in their infancy and their electrochemical performance is unsatisfactory due to the bottlenecks of materials and device design. Therefore, it is of great significance to develop creative air-rechargeable Zn battery systems. Herein, an air-rechargeable Zn battery with H+-based chemistry was developed in a mild ZnSO4 electrolyte for the first time, where benzo[i]benzo[6,7]quinoxalino[2,3-a]benzo[6,7]quinoxalino[2,3-c]phenazine-5,8,13,16,21,24-hexaone (BQPH) was employed as cathode material. In this Zn/BQPH battery, a Zn2+ coordination with adjacent C═O and C═N groups leads to an inhomogeneous charge distribution in the BQPH molecule, which induces the H+ uptake on the remaining four pairs of the C═O and C═N groups in subsequent discharge processes. Interestingly, the large potential difference between the discharged cathode of the Zn/BQPH battery and oxygen triggers the redox reaction between them spontaneously, in which the discharged cathode can be oxidized by oxygen in air. In this process, the cathode potential will gradually rise along with H+ removal, and the discharged Zn/BQPH battery can be air-recharged without an external power supply. As a result, the air-rechargeable Zn/BQPH batteries exhibit enhanced electrochemical performance by fast H+ uptake/removal. This work will broaden the horizons of air-rechargeable zinc batteries and provide a guidance to develop high-performance and sustainable aqueous self-powered systems.

Enhancement of d -wave pairing in the striped phase with nearest neighbor attraction

Recently, the experimental results by the angle-resolved photoemission spectroscopy suggested that an additional strong nearest neighbor attraction in the Hubbard model might be significant to describe the properties of doped cuprates more accurately. The stripe-ordered patterns, formed by the inhomogeneous distribution of spin, charge and pairing correlations in the CuO$_{2}$ planes, is a known feature of doped cuprates. In this work, the effect of the nearest neighbor attraction and the stripe phase are examined by using the constrained path quantum Monte Carlo method within the repulsive Hubbard model on two-dimensional square lattice. The ground state spin correlations along and cross the stripe regions, and the $d$-wave pairing correlation are calculated. It is found that the spin-spin correlation is the highest when the interstripe region is fairly close to half-filling, and $d$-wave superconducting correlation on neighboring sites could be enhanced in the presence of stripe pattern and strong nearest neighbor attraction, which reveals their crucial roles on superconductivity in the doped cuprates.

Influence of local structural distortion on the magnetism of Na2IrO3 compounds

First-principles calculations are conducted to investigate the magnetic properties of the ${\mathrm{Na}}_{2}{\mathrm{IrO}}_{3}$ compounds. We reveal that the ${\mathrm{Na}}_{2}{\mathrm{IrO}}_{3}$'s local structural distortions are essential for an accurate description of the magnetism of such systems. They provide a feasible explanation for the experimentally observed antiferromagnetic zigzag magnetic ground state. We demonstrate that the underlying competition between the spin-orbit coupling and the crystal-field splitting rules the crystal structure and profoundly influences the strength of the magnetic exchange interactions. We unambiguously identify that the ${D}_{4h}$-type distortions, due to the Jahn-Teller effect, are disclosed in an elongation along the ${\mathrm{IrO}}_{6}$ polyhedra's apical axis in the $ac$ plane. On the other hand, the Ir atoms off-centering in the basal plane (perpendicular to the local ${D}_{4h}$ elongation axis) arises owing to an inhomogeneous cationic charge distribution of ${\mathrm{Ir}}^{4+}/{\mathrm{Na}}^{+}$ in the transition-metal layer resulting in both effects being decisive in controlling the magnetism of ${\mathrm{Na}}_{2}{\mathrm{IrO}}_{3}$ together with the spin-orbit interactions.

Single charge control of localized excitons in heterostructures with ferroelectric thin films and two-dimensional transition metal dichalcogenides.

Single charge control of localized excitons (LXs) in two-dimensional transition metal dichalcogenides (TMDCs) is crucial for potential applications in quantum information processing and storage. However, traditional electrostatic doping method by applying metallic gates onto TMDCs may cause inhomogeneous charge distribution, optical quenching, and energy loss. Herein, by locally controlling the ferroelectric polarization of the ferroelectric thin film BiFeO3 (BFO) with a scanning probe, we can deterministically manipulate the doping type of monolayer WSe2 to achieve p-type and n-type doping. This nonvolatile approach can maintain the doping type and hold the localized excitonic charges for a long time without applied voltage. Our work demonstrated that the ferroelectric polarization of BFO can control the charges of LXs effectively. Neutral and charged LXs have been observed in different ferroelectric polarization regions, confirmed by magnetic optical measurement. Highly circular polarization degree with 90% photon emission from these quantum emitters was achieved in high magnetic fields. Controlling the single charge of LXs in a non-volatile way shows a great potential for deterministic photon emission with desired charge states for photonic long-term memory.