Ion Energy Research Articles

Ignition of Self-Sustained <i>Е</i>×<i>В</i> Discharge; Ion Contribution to Understanding the Process

We determined critical values for the ignition voltage and magnetic induction for a self-sustained plasma discharge in crossed electric and magnetic fields, both at inert gases and in their mixtures. As parameters that enabled to visualize igniting an E×B discharge, we used the ion current and the induction current derivative, and provided the temporal characteristics for the process. We found a double structure of the ion current (discharge current) during the ignition. The working media initial state for the discharge current first jump is a neutral gas, whereas the working media initial state for the second jump is plasma. A peak of ions originated within the near-cathode area is detected on the energy distributions of the ions obtained during the ignition. Also detected is a wide ion energy spectrum related to the discharge gap. We show a various discharge ignition character for Penning pairs, when the gas changes its role (main or admixture) in the mixture. The character is determined by features of forming the electric potential distribution in the near-cathode layer.

Energy efficient F atom generation and control in CF4 capacitively coupled plasmas driven by tailored voltage waveforms

Abstract Neutral radicals generated by electron impact dissociation of the background gas play important roles in etching and deposition processes in low pressure capacitively coupled plasmas (CCPs). The rate and energy efficiency of producing a given radical depend on the space- and time-dependent electron energy distribution function (EEDF) in the plasma, as well as the electron energy dependent cross sections of the electron-neutral collisions that result in the generation of the radical. For the case of a CCP operated in CF4 gas, we computationally demonstrate that the energy efficiency of generating neutral radicals, such as F atoms can be improved by controlling the EEDF by using tailored voltage waveforms (TVW) instead of single-frequency driving voltage waveforms and that separate control of the radical density and the ion energy can be realized by adjusting the waveform shape at constant peak-to-peak voltage. Such discharges are often used for industrial etching processes, in which the F atom density plays a crucial role for the etch rate. Different voltage waveform shapes, i.e. sinusoidal waveforms at low (13.56 MHz) and high (67.8 MHz) frequencies, peaks- and sawtooth-up TVWs, are used to study their effects on the energy cost / energy efficiency of F atom generation by PIC/MCC simulations combined with a stationary diffusion model. The F atom density is enhanced by increasing the voltage amplitude in the single frequency cases, while the energy cost per F atom generation increases, i.e. the energy efficiency decreases, because more power is dissipated to the ions, as the sheath voltages and the ion energy increase simultaneously. In contrast, using TVWs can result in a lower energy cost and provide separate control of the F atom density and the ion energy. This is explained by the fact that tailoring the waveform shape in this way allows to enhance the high-energy tail of the EEDF during the sheath expansion phase by inducing a non-sinusoidal sheath motion, which results in acceleration of more electrons to high enough energies to generate F atoms via electron-neutral collisions compared to the single frequency cases. Similar effects of TVWs are expected for the generation of other neutral radicals depending on the electron energy threshold and the specific consequences of TVWs on the EEDF under the discharge conditions of interest.

Influence of bias voltage on the Ar/CH2F2/O2 plasma etching of Si3N4 films

The etching mechanism of silicon nitride (Si3N4) films depending on peak-to-peak bias voltage ( Vpp ) in an Ar/CH2F2/O2 gas-mixture plasmas for high-aspect-ratio etching process was investigated. It was observed that the Si3N4 film etch rate initially decreased with an increase in the Vpp up to 3630 V, but then increased beyond this threshold. This unusual etching behavior can be attributed to the formation of a modified layer on the surface of the Si3N4 film. The characteristics of the modified layer, such as thickness and atomic composition, were found to be strongly influenced by the ion energy and gas chemistry of the process conditions.

Ultrafast synthesis and luminescence properties of rare earth orthoniobates RENbO4 (RE = La, Eu, Gd, Yb, Lu)

Rare earth orthoniobates (RENbO4) are one kind of important functional materials due to its applications in solid-state phosphors, thermal barrier coatings, and microwave dielectric ceramics. The synthesis of rare earth niobates often needs high reaction temperatures (1300 °C–1700 °C) and long processing times (from hours to tens of hours) in solid-state reactions, which can increase the study time of the relationship between structure and properties. In this work, we used ultrafast high-temperature sintering method to synthesize RENbO4 (RE = La, Eu, Gd, Yb, Lu), and found specific structure and properties in these materials obtained with specific synthetic techniques. Based on the electronegativity scale, the charge transfer energy of lanthanide ions in the YNbO4 crystal was calculated. The rapid synthesis of RENbO4 in a vacuum atmosphere generated more oxygen vacancies, and the structures of [REO8] and [NbO6] were distorted. The shortening of the fluorescence lifetime of LaNbO4 and EuNbO4 was related to the formation of self-trapped excitons facilitated by lattice distortion. The emission peak of LuNbO4 at about 530 nm is attributed to the oxygen vacancy in the niobate group. The reported synthetic methods can provide a fast materials screening route for high melting point inorganic materials.

Direct In‐Situ Estimates of Energy and Force Balance Associated With Magnetopause Reconnection

AbstractFundamental processes in plasmas act to convert energies into different forms, for example, electromagnetic, kinetic and thermal. Direct derivation from the Vlasov‐Maxwell equation yields sets of equations that describe the temporal evolution of magnetic, kinetic and internal energies in either the monofluid or multifluid frameworks. In this work, we focus on the main terms affecting the changes in kinetic energy. These are pressure‐gradient‐related terms and electromagnetic terms. The former account for plasma acceleration/deceleration from a pressure gradient, while the latter from an electric field. Although limited spatial and temporal deviations are expected, a statistical balance between these terms is fundamental to ensure the overall conservation of energy and momentum. We use in‐situ observations from the Magnetospheric MultiScale (MMS) mission to study the relationship between these terms. We perform a statistical analysis of those parameters in the context of magnetic reconnection by focusing on small‐scale Electron Diffusion Regions and large‐scale Flux Transfer Events. The analysis reveals a correlation between the two terms in the monofluid force balance, and in the ion force and energy balance. However, the expected relationship cannot be verified from electron measurements. Generally, the pressure‐gradient‐related terms are smaller than their electromagnetic counterparts. We perform an error analysis to quantify the expected underestimation of gradient values as a function of the spacecraft separation compared to the gradient scale. Our findings highlight that MMS is capable of capturing energy and force balance for the ion fluid, but that care should be taken for energy conversion terms based on electron pressure gradients.

Conceptional design of photoneutralization test system for negative ion-based neutral beam injection

Neutral beam injection is one of the effective heating methods in the field of magnetic confinement fusion, and neutralization is the most crucial link in the case of negative ions. To further increase the neutral beam injection power, improve the long pulse operation capability, and optimize the efficiency of the NNBI system, further research and verification about the neutralization mode are needed. Theoretically, photoneutralization can achieve more than 90% neutralization efficiency. However, maintaining stable operation of the megawatt laser cavity over extended periods poses corresponding challenges. Additionally, the cost associated with laser target surpasses the benefit gained from increased neutralization efficiency, leading to its lack of practical application thus far. This paper proposes a solution to these issues by designing a single-channel, multi-fold photoneutralization verification system utilizing the CRAFT NNBI one-quarter and one-half size negative source test equipment. An outline of the system's test and diagnostics approach is provided. Key parameters such as laser target thickness, negative ion energy, beam shape and efficiency of the photoneutralization system are numerically calculated. Combined with the experimental data of the negative source test platform, theoretical calculations show that the neutralization efficiency can achieve 63% with the system efficiency exceeding 40%. Even by increasing the incident laser power or the number of reflections, neutralization efficiency can be increased to 95%, with a simultaneous increase in system efficiency to 60%. Maintaining efficiency while increasing incident laser power could reduce the number of reflections to approximately ten, reaching an acceptable threshold. However, this adjustment will increase the irradiation density of a single mirror from 660W/mm2 increases to 3000W/mm2. This paper methodically designs a practical laser neutralization verification platform, which is expected to substantially improve the neutralization efficiency, and facilitate practical application and validation.

Efficient laser-driven proton acceleration from a petawatt contrast-enhanced second harmonic mixed-glass laser system

Efficient laser-driven plasma acceleration of ion beams requires precision control of the target–plasma profile, which is crucial to optimize the laser energy transfer. Along the laser propagation direction, this can be achieved by tailoring the temporal structure of the laser pulse. We show for the first time that frequency-doubling of a short pulse (hundreds-femtosecond range) petawatt-class mixed-glass laser system, which results in temporal intensity contrast enhancement, enables surface and volumetric laser–energy coupling, and the acceleration of proton beams from few-nanometer-thick foil targets. Experimentally, maximum ion energies and laser-to-proton energy conversion efficiencies were found to be both maximized at optimum laser and target conditions manifested when the normalized target density nearly equalizes the normalized laser vector potential, which is in agreement with theory and simulations. These signatures are recognized as a unique indication of the interaction between ultra-intense laser pulses with high temporal intensity contrast and ultra-thin nanometer-scale targets. Transverse modulations of accelerated proton beams in the form of bubble- and ring-like structures measured in the thinnest targets provide additional evidence of volumetric laser-driven particle acceleration regimes and transitional features in ultra-thin foil targets specific to laser–plasma interactions characterized by a high temporal intensity contrast. These results open avenues in the generation of high contrast laser pulses from short-pulse-femtosecond petawatt mixed-glass laser systems and demonstrate the feasibility of this technique for applications requiring high laser intensity contrast with high efficiency.

Anisotropic wettability transition on nanoterraced glass surface by Ar ions

Ion beam sputtering (IBS) can induce nanoripple patterns in a short time on variety of materials for wide range of applications. In this work, we describe the nanoripple as well as terrace pattern formation by IBS on soda-lime glass surfaces and the mechanisms leading to such pattern formations. The role of ion energy, ion fluence, and ion incidence angle on the morphology of the structural features is systematically explored. For a range of ion beam parameter values with energy varying from 600 to 1500 eV and fluence in the range 9.7 × 1017 to 2.0 × 1019 ions/cm2 at fixed incidence angle of 45°, transition of ripples to terraces has been observed. The experimental results are explained on the basis of recently modified KS equation which clearly explains the simultaneous role of nonlinear cubic term in the terrace formation. It is also demonstrated how ion beam can be used to tailor the wettability of glass surface and makes it hydrophobic in nature. Due to pattern formation, anisotropic hydrophobicity is observed showing an increasing trend owing to the magnification of the amplitude of nanopatterns developed on the surface.

Modeling swift heavy ion irradiation of substrate-supported two-dimensional material via two-temperature molecular dynamics simulations

This study employs two-temperature molecular dynamics simulations to investigate swift heavy ion irradiation of SiO2 substrate-supported two-dimensional material graphene. Material-dependent electronic and thermal properties are integrated into each region to model the energy transfer between the electronic and atomic subsystems of the studied materials. Simulations of interactions with Xe heavy ions are performed with ion kinetic energies ranging from 0.5 to 25 GeV with electronic stopping powers from ∼2.6 to 17.7 keV/nm. With the studied ion energy range, nanopores with a diameter of up to 5 nm can be formed in graphene due to the thermally driven sputtering effect, while amorphization occurs along the ion track in the SiO2 substrate. The coupling between the substrate and two-dimensional material significantly impacts the structural change due to heat transfer and atomic interactions among different layers of materials. The method applied in this work provides a valuable tool for modeling and understanding the structural modifications induced by ion irradiation in layered structures.

In situ measurement of electron emission yield at Si and SiO2 surfaces exposed to Ar/CF4 plasmas

Abstract Plasma simulations require accurate yield data to predict the electron flux that is emitted when plasma-exposed surfaces are bombarded by energetic particles. One can measure yields directly using particle beams, but it is impractical to create a separate beam of each particle produced by typical plasmas. In contrast, measurements made in situ, during plasma exposure, provide useful values for the total emitted flux and effective yield produced by all incident particles. Here, in situ measurements were made at thermally oxidized and bare silicon wafers placed on the radio-frequency (rf) biased electrode of an inductively coupled plasma system. The rf current and voltage across the sheath at the wafer were measured, along with Langmuir probe measurements of ion current density and electron temperature. The measurements are input into a numerical sheath model, which allows the emitted electron current to be distinguished from other currents. The effective yield, i.e. the ratio of the total emitted electron flux to the incident ion flux, was determined at incident ion energies from 40 eV to 1.4 keV, for Si and SiO2 surfaces in Ar, CF4, and Ar/CF4 mixtures at 1.33 Pa (10 mTorr). Yields for Ar plasmas are compared with previous work. For SiO2 surfaces in Ar/CF4 mixtures and pure CF4, the yield is dominated by ion kinetic emission, which is the same for all mixtures, and, presumably, for all ions. For Si surfaces in Ar/CF4 and CF4, the yield at high energies can be explained in part by fragmentation of molecular ions, and the yield from Ar+ can be distinguished from the other ionic species. Analytic fits of the yields are provided for use in plasma simulations.

Design and initial results of the imaging neutral particle analyzer in large helical device.

A novel Imaging Neutral Particle Analyzer (INPA) was newly installed in early 2024 to enhance the understanding of fast ion confinement on Large Helical Devices (LHDs). This diagnostic system, based on a magnetic spectrometer using a scintillator, provides energy-resolved radial profiles of confined fast ions by measuring charge-exchanged fast neutrals escaping from the plasma. The system utilizes a 100nm thick carbon foil to ionize the fast neutrals, subsequently deflecting the ions toward a scintillator via the existing local magnetic field. The fast ion energy and sightline determine the position of the scintillation, while the light intensity depends on the flux of the fast ions. The INPA features two apertures, facilitating effective measurements in both clockwise and counterclockwise magnetic field directions in the LHD. This INPA was designed as a passive measurement system that measures fast ions charge exchange with background neutrals, focusing on perpendicular beam ions from 5 to 100keV with an energy resolution of about 5.75keV. This paper describes the details of the design, installation, and the initial results of the INPA on the LHD. This work will contribute significantly to a deeper understanding of fast ion transport due to magnetohydrodynamic instabilities.

Differential Abundance of Protein Acylation in Mycobacterium tuberculosis Under Exposure to Nitrosative Stress.

Human macrophages generate antimicrobial reactive nitrogen species in response to infection by Mycobacterium tuberculosis (Mtb). Exposure to these redox-reactive compounds induces stress response in Mtb, which can affect posttranslational modifications (PTM). Here, we present the global analysis of the PTM acylation of Mtb proteins in response to a sublethal dose of nitrosative stress in the form of nitric oxide (NO) using label free quantification. A total of 6437 acylation events were identified on 1496 Mtb proteins, and O-acylation accounted for 92.2% of the events identified, while 7.8% were N-acylation events. About 22% of the sites identified were found to be acylated by more than one acyl-group. Furthermore, the abundance of each acyl-group decreased as their molecular weight increased. Quantitative PTM analysis revealed differential abundance of acylation in proteins involved in stress response, iron ion homeostasis, growth, energy metabolism, and antimicrobial resistance (AMR) induced by nitrosative stress over time. The results reveal a potential role of Mtb protein acylation in the bacterial stress responses and AMR. To our knowledge, this is the first report on global O-acylation profile of Mtb in response to NO. This will significantly improve our understanding of the changes in Mtb acylation under nitrosative stress, highly relevant for global health.

Simulation Study of Crystalline Al2O3 Thin Films Prepared at Low Temperatures: Effect of Deposition Temperature and Biasing Voltage

In this paper, classical molecular dynamics simulations were used to explore the impact of deposition temperature and bias voltage on the growth of Al2O3 thin films through magnetron sputtering. Ion energy distributions were derived from plasma mass spectrometer measurements. The fluxes of deposited particles (Ar+, Al+, and O−) were categorized into low, medium, and high energies, and the results show that the films are dominated by amorphous Al2O3 at low incident energies without applying bias. As the deposition temperature increased, the crystallinity of the films also increased, with the crystals predominantly consisting of γ-Al2O3. The crystal content of the deposited films increased when biased with −20 V compared to when no bias was applied. Crystalline films were successfully obtained at a deposition temperature of 773 K with a −20 V bias. When biased with −40 V, crystals could be obtained at a lower deposition temperature of 573 K. Increasing the bias enables the particles to have higher energy to overcome the nucleation barrier of the crystallization process, leading to a greater degree of film crystallization. At this stage, the average bond length between Al-O is measured to be approximately 1.89 Å to 1.91 Å, closely resembling that of the crystal.

Hybrid simulation of a capacitive Ar/SiH4 discharge driven by electrically asymmetric voltage waveforms

Voltage waveforms associated with the electrical asymmetry effect (EAE) have the potential to be used in the deposition of the silicon-based film, since they are expected to decouple ion energy and flux at the wafer surface, and further facilitate control of the process. In this study, a one-dimensional fluid/electron Monte Carlo hybrid model is employed to examine the EAE in a capacitively coupled argon-silane discharge, encompassing both amplitude asymmetry effect (AAE) and slope asymmetry effect (SAE). In the case of AAE, with the increasing pressure, the discharge electronegativity gradually intensifies, in conjunction with a transition of the electron heating mode from α to drift-ambipolar, a reduction of the absolute value of the DC self-bias voltage, and a decrease in Ar+ content, with an increase in SiH3 + content. For SAE, the trend in the discharge characteristics with the increasing pressure is similar to that for AAE, but the details are different. In SAE, the electronegativity and bulk electric field are much enhanced, resulting in higher content of high-energy electrons and Ar+ in the bulk. In addition, the absolute value of the self-bias is lower, but shows a fewer decline with the increasing pressure. The deposition rate is lower in SAE, due to the lower electron heating efficiency. However, larger voltage drop difference between two sheaths leads to a wider range of ion energy modulation at higher pressures. This study systematically investigates and compares Ar/SiH4 discharges driven by two electrically asymmetric voltage waveforms across various parameters including electron dynamics, ion and neutral transport properties, and deposition rates, with the aim of providing valuable insights and a reference for industrial applications.

Sputtering yield increase with fluence in low-energy argon plasma-tungsten interaction

The increase of tungsten sputtering yield with fluence was investigated during plasma (≤100 eV) irradiation. This analysis focused on the combined effects of surface binding energy and surface morphology caused by Ar retention. As post-mortem analysis, Ar concentration was measured with SIMS (Secondary Ion Mass Spectroscopy) and TDS (Thermal Desorption Spectroscopy). The Ar concentration saturated at 21 % of W number density during the sputtering process. The corresponding change in surface morphology causes a change in the local ion incident angle, which leads to a sputtering yield increase of 10 %. The increased Ar concentration leads to a decrease in surface binding energy and a change in surface morphology which increases W sputtering yield from 0.02 to 0.03 by ion energy 80 eV. Over time, W sputtering yield reaches saturation as a function of saturated Ar concentration. This result implies that the synergistic role of Ar concentration and surface morphology on sputtering yield. This sputtering yield enhancement occurs more seriously in the realistic condition of plasma-facing materials that face low-energy plasma.

Far-field plume characterization of a low-power cylindrical Hall thruster

A fully cylindrical Hall thruster prototype was tested in the power range of 30–300 W with the objective of understanding the behavior of the discharge as a function of input parameters. Various operating conditions were compared, including two magnetic field configurations, a set of propellant mass flow rates, and a range of discharge voltages. Plasma properties were measured in the plume, with a Langmuir probe, a retarding potential analyzer, and a Faraday cup. The experimental results showed that the mass flow rate strongly affects the ionization and, consequently, other related properties such as the plasma density, currents, and propellant utilization. The discharge voltage also appeared to influence the ion energy and propellant utilization. The performance accessible from the measured magnitudes is assessed, resulting in a maximum thrust efficiency of about 18% at 0.35 mg s−1 and 168 W.

Correlation between Crystallite Characteristics and the Properties of Copper Thin Film Deposited by Magnetron Sputtering: Bias Voltage Effect

This work investigates the properties of copper thin films deposited by magnetron sputtering. The substrate is biased by a negative voltage (Vs), which controls the energy ions bombardment during the deposition of the thin films. In order to focus solely on the ions energy contribution, the power supply was fixed and the working pressure was selected at 5 Pa. This ensures energetic sputtered particles completely thermalized, by a sufficient number of collisions with the Argon gas. X-ray diffraction analysis revealed that substrate voltage Vs affects essentially the structure and size of the formed crystallites. The preferred orientation (111) and the larger crystallite size (30 nm) were achieved at Vs = - 60 V. The Cu (111)/(200) peak intensity ratio is maximal (12.55) at - 60 V, corresponding to the lowest resistivity value (6.33 mW.cm). Optimum corrosion resistance of the deposited thin film was achieved at -60 V. At high crystallite sizes, nanoindentation analysis showed a thin film that is more elastic (133 GPa) and less hard (1.96 GPa).

The effect of the electron κ-distribution on the dust particle charging in the radio-frequency thermal-sheaths

In order to investigate collisionless radiofrequency plasma sheaths containing dust particles, three models are utilized: the novel kinetic scheme Ensemble-in-Spacetime (EST) model for calculating sheath parameters, the Dust Particle Charging model, and the Single Dust Particle model. The EST model has been modified to account for κ-electron distributions. This model is applicable to radiofrequency plasma sheaths found in tokamaks equipped with an ion cyclotron radiofrequency (ICRF) wave heating system, such as JET, West(Tore Supra), EAST, ASDEX-U, and KSTAR. The calculated sheath parameters are utilized to determine the electron and ion currents of the dust particles. In the intermediate radio-frequency regime, when the ion plasma frequency is comparable to the ICRF, the flux and energy of the ions are modulated in time within the sheath. The ions are not inertialess, and the value of κ affects the electron and ion densities. As the value of κ increases, the time-averaged electron and ion densities, sheath edge position, and area of the sheath voltage-sheath charge hysteresis loop also increase. However, the ion energy distribution remains insensitive to the κ distribution. The dust particles are charged with different negative charges based on their radius, position within the sheath, κ-electron distribution, and sheath potential. These particles exhibit oscillatory motion due to their interactions with the plasma and gravitational fields and are accelerated toward the plasma core.

Tandem Mass Spectrometry Approaches for Differentiation and Quantification Pidotimod and Its Three Isomers in the Gas Phase.

Pidotimod is a chiral drug that possesses two chiral centers, resulting in three isomeric impurities (analytes, A). This study employs electrospray ionization ion trap mass spectrometry (ESI-MS) through collision-induced dissociation (CID) to investigate the chiral recognition of pidotimod and its three isomers to eliminate chromatographic separation. Three approaches were explored: (1) Protonated molecules in CID exhibited discriminative potential for diastereomers, with the ability to distinguish between S,S and R,R configurations, albeit with an Rchiral value of ~1.8. However, differentiation between R,S and S,R configurations was not achievable. (2) Alkali adductions (lithium and sodium) only discerned diastereomers. The Rchiral values of the diastereomers obtained from alkali adduct ions were significantly lower than those obtained from protonated ions. (3) Therefore, a third approach was used to address the challenge of distinguishing between R,S and S,R configurations, including the introduction of chiral references (ref) and transition metals (MII) to form metal-bound complexes [MII(A)(ref)-H]+. Additionally, we synthesized a novel ligand, 4-(N-tert-butoxycarbonyl [Boc]-L-prolinamido)phenol (denoted as ligand A), by modifying N-t-Boc-L-Pro with 2-aminophenol, which, in combination with CuII and NiII, enabled simultaneous differentiation of all four isomers. CuII complexes exhibited significant chiral selectivity between R,S and S,R configurations. Density functional theory calculations were performed to further elucidate the stereodynamic behavior and stoichiometry of these ions in the gas phase. These calculations revealed the interaction energy and coordination sites of the precursor ions in the gas phase, correlating well with MS/MS experiment results. Additionally, the logarithm of the CuII complexes' characteristic fragment ion abundance ratio demonstrated a strong linear relationship with enantiomeric excess (ee). This study presents a novel strategy for chiral drug quality control that eliminates chromatographic separation.

Tunable Hydrogen-Related Defects in ZnO Nanowires Using Oxygen Plasma Treatment by Ion Energy Adjustment.

The chemical bath deposition (CBD) process enables the deposition of ZnO nanowires (NWs) on various substrates with customizable morphology. However, the hydrogen-rich CBD environment introduces numerous hydrogen-related defects, unintentionally doping the ZnO NWs and increasing their electrical conductivity. The oxygen-based plasma treatment can modify the nature and amount of these defects, potentially tailoring the ZnO NW properties for specific applications. This study examines the impact of the average ion energy on the formation of oxygen vacancies (VO) and hydrogen-related defects in ZnO NWs exposed to low-pressure oxygen plasma. Using X-ray photoelectron spectroscopy (XPS), 5 K cathodoluminescence (5K CL), and Raman spectroscopy, a comprehensive understanding of the effect of the oxygen ion energy on the formation of defects and defect complexes was established. A series of associative and dissociative reactions indicated that controlling plasma process parameters, particularly ion energy, is crucial. The XPS data suggested that increasing the ion energy could enhance Fermi level pinning by increasing the amount of VO and favoring the hydroxyl group adsorption, expanding the depletion region of charge carriers. The 5K CL and Raman spectroscopy further demonstrated the potential to adjust the ZnO NW physical properties by varying the oxygen ion energy, affecting various donor- and acceptor-type defect complexes. This study highlights the ability to tune the ZnO NW properties at low temperature by modifying plasma process parameters, offering new possibilities for a wide variety of nanoscale engineering devices fabricated on flexible and/or transparent substrates.