Copper nanowires (CuNWs) have a wide range of applications in flexible electronics due to their excellent electrical conductivity, mechanical flexibility, optical transparency, and cost-efficiency. However, CuNWs are highly susceptible to oxidation, which limits their applications. In this study, CuNWs were synthesized by the hydrothermal method, and a time-efficient CuNWs-Ag core-shell nanostructure synthesis was developed, which prevented oxidation by coating Ag on CuNWs. The Ag plating process was optimized by adjusting the reaction time of the Ag plating and the amount of CuNWs added to the silver amine solution. The results showed that the synthesis time of the CuNWs-Ag core-shell nanostructure obtained through the galvanic replacement reaction method was significantly reduced. Optical and structural measurements confirmed the oxidation resilience. The output performance of triboelectric nanogenerators (TENGs) in single-electrode (SE) mode was studied, and the SE-TENG-based on CuNWs-Ag core-shell nanostructure, showed markedly improved stability compared to SE-TENG-based on pristine CuNWs, which was also exemplified by LED lighting from the electrical energy obtained from the TENGs in real-time. Given the fact that these modified CuNWs can be used in a variety of electronic and optoelectronic applications, these results hold great promise.

Solution peeling of perovskite single crystals for the fabrication of stable and highly efficient phosphors.

Printable mesoscopic perovskite solar cells (MPSCs) hold significant potential as a low-cost photovoltaic technology. In this study, iron oxide (Fe3O4) modified carbon electrode were innovatively used to optimize the interfacial performance in MPSCs. The devices with different mass ratios of Fe3O4 to graphite were fabricated by printing method. With the multi-effects of the Fe3O4-modified CEs, a 16.43% efficiency of the device (CFe3O4-0.15) was achieved, which was 10.6% higher than the control device using standard carbon electrodes. Simultaneously, the device (C-Fe3O4-0.15) retained 96% of their highest PCE, which was higher than 72% of the control device after 1000 h at room temperature condition. This research provides a scalable solution for enhancing the stability of MPSCs through electrode engineering.

Perovskite materials have attracted substantial attention for their promising applications in high-performance light-emitting devices. However, the development of cyan-emissive metal halide perovskites lags markedly behind their red and green counterparts among the multi-color emissive type perovskites, primarily because of their poor stability and low luminescence efficiency. Herein, PbBr(OH)-encapsulated and Zn-doped MAPbBrxCl3-x (MA = CH3NH3+) cyan phosphors were fabricated by in situ solution peeling from Zn-alloyed MAPbBrxCl3-x single crystals. Notably, the PbBr(OH) shell-encapsulated perovskite phosphors not only demonstrate excellent stability under light, heat, and exposure to organic solvents but also confine the photogenerated excitons, passivate surface defects, prevent ion migration and suppress non-radiative losses in the MAPbBrxCl3-x nanocrystals upon Zn doping, resulting in a high photoluminescence quantum yield (PLQY). As a representative candidate, the Zn:MAPbBr2.2Cl0.8@PbBr(OH) phosphor exhibits a bright cyan emission at 481 nm with a high PLQY of over 90%. The Zn:MAPbBr2.2Cl0.8@PbBr(OH) phosphor-based cyan light-emitting diode maintains a brightness exceeding 1000 cd m-2 even after 24 h of continuous operation under a current of 9.8 mA with exceptional stability. Furthermore, these cyan-emissive phosphors can be utilized for overcoming the issues of "blue overshoot" and "cyan gap" in white light-emitting diodes.

Electro-Spun nanofibers (ESNs), with their design flexibility, tailorable morphologies, and high surface area, are well-favored as triboelectric nanogenerator (TENG) materials for wearable electronics. Here, various aspects of ESNs-based wearable TENGs were examined. After introducing the most common TENG operating modes, an insightful overview of wearable TENG applications based on ESNs was presented. In this survey, a special attention is paid to wearable sensing, human-machine interaction, self-powered devices, and amplified energy harvesting. Efforts towards improving energy conversion efficiency, material durability, and compatibility with diverse wearable platforms were visited. Finally, a perspective based on particularly material aspect of ESNs is given, which could be insightful in tackling prevailing challenges and giving birth to new directions.

Triboelectric nanogenerators (TENGs), as an emerging energy harvesting device, can efficiently convert the weak mechanical energy in the environment into electrical energy, demonstrating significant potential in self-powered systems. In this study, polyvinylidene fluoride (PVDF) nanofiber films mixed with a small amount of n-propyl gallate (PG) were prepared by using the electrospinning technique, and TENGs were fabricated based on these films. Unexpectedly, experimental results showed that PG (with 0.5–2.5 wt%) did not affect the β phase of the PVDF. However, the TENG based on PVDF/PG composite nanofiber film with 1 wt% PG (PG1-TENG) exhibited large output values of 334 V, 4.36 μA, and 78.4 nC for output voltage, current, and transferred charge, respectively, with a power density of 5.27 W/m2, which highlights ~60% improvement in output voltage over pristine PVDF-TENG. This observation was attributed to the unique charge regulation ability of PG, without altering PVDF’s β phase. Furthermore, application potential of PG1-TENG was demonstrated by powering up an LCD calculator and 480 LEDs.

Mixed halide perovskite CsPbBrxI3-x nanocrystal (NC) films exhibit viable application prospects in pure red perovskite light-emitting diodes (PeLEDs). However, intrinsic environmental instability, defects, and spectral instabilities are always present in pure red perovskites under mixing halide ion exchange processing. In this work, we developed a swelling method for the preparation of stable pure red light emission Zn: CsPbBrxI3-x-PVDF films by post-treatment with CsBr-ZnI2 at room temperature. In this system, PVDF-CsBr-ZnI2 presents triple synergistic effects to control anion exchange, stabilize the crystal structure, and passivate the defects of the red CsPbBrxI3-x-PVDF film, simultaneously. In addition, the Zn: CsPbBrxI3-x-PVDF films' photoluminescence emission can be precisely tuned from 665 to 580 nm with high spectral stability. More importantly, the as-prepared 637 nm emitting Zn: CsPbBrxI3-x-PVDF films present a full width at half-maximum (fwhm) as narrow as 50 nm with a high photoluminescence quantum yield (PLQY) of more than 47.27% after annealing. It was also demonstrated to serve as conversion layers for stable pure red LEDs, achieving the CIE Rec. 2020 standard and sustained electrical stability. The trinity of halide exchange, Zn passivation, and polymer encapsulation provides a novel strategy for obtaining high-quality perovskite lighting flexible thin films.

Nonlinear photocurrents (NPs) are electrical currents expected to be measured at the electrodes of a device consisting of an active area, sensitive to light, with a higher-order in-electric field where light-impinging geometry (LIG) is the determining factor in the experimental observation. Although the phenomenology of this light–matter interaction is clear for light directed on a lateral device plane with well-defined azimuthal and incidence angles, as well as light polarization angle, it can be quite complicated for a vertical device structure and reconsideration of the expected NP contributions is necessary in the latter case. In this study, we used a visual approach to describe the LIG for vertical device structures using a specific example of a photodiode, and showed that these angles must be redefined, namely, the interchangeability of azimuthal and incidence angles. The influence of device geometry-dependent optical illumination is reflected on the behavior of NP; therefore, the NPs that are known to be forbidden in certain LIGs can be allowed and vice versa. These results pave the way for the utilization of NPs in flexible optoelectronic applications.

Water evaporation-induced electricity generator (WEG) is a highly promising approach to harness the power of water evaporation. In this study, a robust TiO2-C bi-layer WEG (TC-WEG) based on a conductive glass (FTO) substrate has been developed through a simple method in which the TiO2 layer was made by the doctor-blade method and the carbon black (CB) layer by the flaring method. The open-circuit voltages (Voc) and shortcircuit currents (Isc) of the TC-WEGs exhibited a near-linear relationship to the evaporative height and width of the TC-WEGs respectively. The 1.5 cm by 8 cm TC-WEG could consistently produce a high V oc over 1.5 V and an I sc exceeding 400 nA under ambient conditions. Despite prolonged exposure to water immersion, the TC-WEG kept its structural integrity and ensured a consistent and stable electrical output without any degradation. The TC-WEG, characterized by its easy fabrication and high cost efficiency, possesses substantial practical potential for harnessing renewable energy sources.

In this study, a novel tunnel structure vanadate NaVO (Na0.465V2O5) cathode for aqueous zinc ion batteries (AZIBs) is facilely fabricated by thermal decomposition of polyoxovanadate containing NH4+ ions. The NaVO cathode is characterized by abundant oxygen vacancies and nanometer dimensions. These attributes can offer extra reaction sites and suppress structural collapse during circulation. In the charge-discharge process, a unique phenomenon occurs where NaVO undergoes opposite expansion (positive vs. negative expansion) along its different crystal planes. This opposite expansion produces an "expansion counteraction effect", which effectively buffers the volume change of NaVO. Additionally, the irreversibly inserted Zn2+ ions as "pillars" are maintained in the framework after the first discharge, further improving the structural stability of NaVO. Consequently, the NaVO cathode exhibits superior cycling stability. The capacity retention rate can reach 87.3% after 350 cycles at 0.1 A g-1. With a high current density of 2 A g-1, the specific capacity can be maintained at 206.3 mA h g-1 with a capacity retention of 95.5% after 2100 cycles. This study not only provides a novel approach for synthesizing nanoscale vanadate cathodes with rich oxygen vacancies, but also proposes the "expansion counteraction effect" theory, offering innovative insights into the design of high cycling stability cathodes for AZIBs.

GaN/AlGaN multiple quantum well light-emitting diodes (MQW-LEDs) are high-performance electroluminescent sources with broad applications in solid-state lighting, medical diagnostics, and industrial processing. This study systematically investigates the ultraviolet (UV) emission mechanisms and wavelength-tuning strategies of GaN/AlGaN MQWs through Technology Computer-Aided Design (TCAD) simulations. Unlike conventional GaN heterojunction LEDs, the emission characteristics of the MQW-LEDs are governed by quantum confinement effects (QCE) and polarization field engineering. By optimizing structural parameters, we achieve tunable UV emission across 335–366 nm, with optimized electroluminescence (EL) centered at 342.6–348.7 nm. Deconvolution analysis of EL spectra reveals that the emission blue shift originates from enhanced QCE due to reduced well thickness-an effect that not only increases carrier wavefunction overlap and radiative recombination efficiency by also suppress non-radiative recombination losses by minimizing lattice relaxation and interfacial strain accumulation. These findings establish critical design guidelines for bandgap engineering in nitride-based MQWs and provide theoretical foundations for developing high-efficiency UV LEDs.

Energy efficiency vs. degradability of materials making up triboelectric nanogenerators (TENGs) is critical for recyclable energy sources. In this work, we first compared voltage output expectation (Vexp) of contact-separation TENG consisting of two tribo-layers: paper and common plastics used in packaging (both non-biodegradable and biodegradable). Detailed analysis based on atomic force microscopy and capacitance measurements demonstrated surface roughness of soft-rough biodegradable polymers (SRBPs) is expected to yield larger Vexp, predictably. A SRBP composite-based TENG was expected to show ∼7.2 times larger Vexp than a hard-flat nonbiodegradable plastic, demonstrating promising charge transfer efficiency; while the measured voltage (Vmea) was only 6.5% of Vexp. This was unlike the other plastics, including a non-composite SRBP, (Vmea/Vexp ∼0.36) and the low Vmea/Vexp in the SRBP composite-based TENG was attributed to intrinsic material properties. Also, energy conversion efficiency in TENG-based on SRBPs was more than double of hard-flat plastics. This shows the potential of the composite SRBP-based TENG as effective energy harvester.

In this study, a novel cathode material comprising VO2/V2O3/V6O13@nitrogen-doped carbon nanosheets (denoted as VO2/V2O3/V6O13@N-C) with abundant oxygen vacancies was synthesised for aqueous zinc-ion batteries (AZIBs). The synthesis was achieved via a self-sacrificial route utilising an organic-inorganic hybrid layered vanadate precursor, [(CH3)2NH2]V3O7. The presence of oxygen vacancies and multiple heterostructures within the cathode facilitates the diffusion of Zn2+ ions and provides additional active sites for electrochemical reactions. Furthermore, the nanosheet morphology and the nitrogen-doped carbon coating synergistically enhance the electronic conductivity of the cathode. Notably, during the charging and discharging processes, an opposing lattice expansion phenomenon (i.e., positive versus negative expansion) occurs between the VO2/V2O3 and V6O13 phases, leading to an "expansion counteraction" effect that effectively mitigates volumetric changes in the VO2/V2O3/V6O13@N-C cathode. Consequently, the VO2/V2O3/V6O13@N-C cathode exhibits outstanding rate performance and cycling stability. Specifically, the discharge capacity reaches 290.1 mA h g-1, with a remarkable capacity retention rate of 95.6% after 250 cycles at a current density of 0.2 A g-1. Furthermore, at a high current density of 5 A g-1, the cathode achieves a maximum discharge capacity of 198.2 mA h g-1 and retains 86.5% of maximum capacity after 2000 cycles. This study not only proves that calcination of organic-inorganic hybrid layered vanadate is a promising approach for synthesizing high-performance vanadium oxide cathodes, but also presents the "expansion counteraction" strategy to tackle the issue of volume changes for vanadium oxide cathodes.

The space charge limited current of amorphous organic semiconductors with an exponential density of states (EDOS-SCLC model) resembles the same dependence of bias with the trap limited current (TLC model) case. The similarity of these two current density formulas may course an overestimation of the influence of the free and trapped charges on current density when interpreting experimental data. We promote a transparent model incorporating both the influences of the free and the trapped charges on the current density. The model can be simplified into the EDOS-SCLC model and the TLC model in limiting conditions. When the influences of the free and the trapped charges are comparable, a transition of the slope of the current-voltage curve appears. When compared with experimental results, satisfactory agreement is obtained. What's more, the influence of dilution of narrow band materials into wide band matrix on the current density is discussed.

Heterostructure engineering and oxygen vacancy engineering are the most promising modification strategies to reinforce the Zn2+ ion storage of vanadium oxides. Herein, a rare mixed-dimensional material (VOx), composed of V2O5 (2D), V3O7 (3D), and V6O13 (3D) heterostructures, rich in oxygen vacancies, was synthesized via thermal decomposition of layered ammonium vanadate. The VOx cathode provides an exceptional discharge capacity (411 mA h g-1 at 0.1 A g-1) and superior cycling stability (the capacity retention remains close to 100% after 800 cycles at 2 A g-1) for aqueous zinc-ion batteries (AZIBs). Ex situ characterizations confirm that the byproduct Zn3V2O7(OH)2·nH2O is generated/decomposed during discharge/charge processes. Furthermore, VOx demonstrates reversible intercalation/deintercalation of H+/Zn2+ ions, enabling efficient energy storage. Remarkably, a reversible crystal-to-amorphous transformation in the V2O5 phase of VOx during charge-discharge was observed. This investigation reveals that mixed-dimensional heterostructured vanadium oxide, with abundant oxygen vacancies, serves as a highly promising electrode material for AZIBs, further advancing the comprehension of the storage mechanism within vanadium-based cathode materials.

Printable HTM-free (HTM = hole -transporting material) mesoporous carbon -based perovskite solar cells (C-PSCs) are one of the most promising technologies. In this study, a high -quality chlorinated mesoscopic TiO2 (m-TiO2) film was obtained by hydrochloric acid (HCl) wet chemical process and applied in C-PSCs based on TiO2/ZrO2/ (5-AVA)x(MA)1-xPbI3/C structures. Experimental results show that the PCE of chlorinated m-TiO2 C-PSCs greatly improved. Based on (5-AVA)x(MA)1-xPbI3, C-PSCs with TiO2 ETL treated with HCl aqueous solution achieved an average photovoltaic conversion efficiency of 9.36 %, which is an increase of 7.96 % in comparison with the efficiency of the device using unmodified TiO2 ETL, while the Voc and the Jsc were increased by 3.63 % and 2.63 %, respectively. In a 30 -day aging test, C-PSCs based on (5-AVA)x(MA)1-xPbI3 and TiO2-HCl 1 exhibited excellent stability under ambient air conditions.

Virtual instrument technology has been increasingly used in university physics experiment teaching. An experimental platform is specifically constructed for studying low-frequency vibrations in university physics, which is based on a computer and its internal sound card, along with a program developed in LabVIEW programming environment to perform control and measurement on our experimental platform. The proposed platform effectively replaces the conventional signal generator and oscilloscope traditionally used in such experiments by integrating virtual instruments and essential experimental equipment. The platform offers various functionalities, such as synchronous transmission and reception of low-frequency signals, frequency measurement, dynamic frequency sweep measurement, and measurement using the three-point approximation method. The proposed platform has been successfully applied in experiments involving forced vibration, resonance of tuning forks, and dynamic measurement of Young's modulus. Unlike conventional low-frequency vibration experiments, the proposed experimental platform optimizes efficiency, reduces costs, and offers opportunities for enhancing the instructional content of experiments. Furthermore, the incorporation of state-of-the-art computer technology enhances students' engagement and enthusiasm for learning.

The carrier transport in amorphous organic semiconductors with an exponential density of states is systematically studied under the framework of admittance spectroscopy. Due to the exponential distribution, the slope of the double logarithmic curve of current density versus voltage is expressed as b+2, where b relates to the width of the density of states. And the mobility is proportional to nb, where n is the density of carrier. In this case, the peak frequencies of the negative differential susceptance and imaginary part of impedance turn out to be functions of parameter b. Therefore, the relation between transit time and mobility will be a linear function of parameter b. Applying our model to interpret experimental data of both small molecular and polymeric materials are illustrated. The contributions of electric field and of carrier density to mobility are discussed.

Multiple quantum-wells light-emitting diodes (MQWs-LEDs) are high-performance electroluminescent light sources, which is widely used in solid state lighting, medical, industrial and other fields. Understanding the light emission origin and mechanisms of MQWs-LEDs is crucial for their practical applications. Here, we show the excellent ultraviolet (UV) and deep-ultraviolet (DUV) emissions from ZnO/AlGaN MQWs-LEDs using Technology Computer Aided Design (TCAD) simulation, which deviates from the typical ZnO heterojunction LEDs. The adjustment of the structural parameters of the MQWs was performed to control the emission wavelength in the range of 335–366 nm. After parameter optimization, 342.6–348.7 nm DUV EL from ZnO/AlGaN MQWs is obtained successfully. The deconvolution analysis of the EL spectra was conducted to investigate the origin of the emissions. The results indicate that the structural parameter operation-induced emission blue-shift results from the quantum confinement effect. This work provides new references for designing ZnO-based MQWs and preparing new DUV LEDs.

PbX(OH) (X = Cl, Br, I) is considered one of the effective encapsulation matrixes to improve the stability and luminescence efficiency of perovskites. Several strategies have been explored to construct perovskite@PbBr(OH) composites with high photoluminescence quantum yield. However, there is limited research on their precise growth kinetics mechanism and morphology control. Herein, PbBr2 microwires (MWs) were applied to act as the lead source and serve as a skeleton frame for the growth of CH3NH3PbBr3 (MAPbBr(3)) MWs. The structure transition from MAPbBr(3) to MAPbBr(3)@PbBr(OH) MWs was triggered by the synergistic effect of H2O and CH3NH3OOCCH3 (methylamine acetate, MAAc). All components and synthesis processes used in this system are explicit, which allows a more in-depth exploration of the MAPbBr(3)@PbBr(OH) formation kinetics. The results indicate that the hydrolysis of MAAc provides OH- and partly replaces Br- ions in MAPbBr(3) to form the MAPbBr(x)Ac(3-x) intermediate, which induces the transformation of MAPbBr(3) into PbBr(OH) until the stable MAPbBr(3)@PbBr(OH) microwires are formed. Based on this growth kinetics process, utilizing H2O-MAAc and extra sodium halide (NaCl, NaI) mixture can synthesize MAPbBr(n)X(3-n)@PbX(OH) (X = Cl, I) microwires successfully. Our study can open a new avenue for developing high-efficiency and high-stability fluorescent hybrid perovskites for three primary color detectors, lasing cavities, and sensors.