Ag Ion Implantation Research Articles

Deflecting Dendrites by Introducing Compressive Stress in Li7La3Zr2O12 Using Ion Implantation.

Lithium dendrites belong to the key challenges of solid-state battery research. They are unavoidable due to the imperfect nature of surfaces containing defects of a critical size that can be filled by lithium until fracturing the solid electrolyte. The penetration of Li metal occurs along the propagating crack until a short circuit takes place. It is hypothesized that ion implantation can be used to introduce stress states into Li6.4La3Zr1.4Ta0.6O12 which enables an effective deflection and arrest of dendrites. The compositional and microstructural changes associated with the implantation of Ag-ions are studied via atom probe tomography, electron microscopy, and nano X-ray diffraction indicating that Ag-ions can be implanted up to 1µm deep and amorphization takes place down to 650-700nm, in good agreement with kinetic Monte Carlo simulations. Based on diffraction results pronounced stress states up to -700MPa are generated in the near-surface region. Such a stress zone and the associated microstructural alterations exhibit the ability to not only deflect mechanically introduced cracks but also dendrites, as demonstrated by nano-indentation and galvanostatic cycling experiments with subsequent electron microscopy observations. These results demonstrate ion implantation as a viable technique to design "dendrite-free" solid-state electrolytes for high-power and energy-dense solid-state batteries.

Defect-Induced Phase Transformations in CuO Thin Films by Ag Ion Implantation and Their Gas-Sensing Applications

The present study is aimed to modify the structural, optical, and morphological properties of CuO thin films with Ag ion implantation toward their potential applications. Fabrication of thin films of CuO was carried out using a thermal evaporation technique on silicon (Si) substrate; post implantation was done with 30 keV Ag ions with varying fluences from 1 × 1014 to 1 × 1016 ions/cm2. The pristine and implanted samples were characterized through X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM), and diffused reflectance spectroscopy (DRS). SRIM simulation was also carried out to understand the range and other effects. XRD measurements confirmed the formation of the CuO phase for pristine samples, and with the increase in ion fluence, the chemical composition changed from pure CuO to Cu2O + CuO and then to Cu2O + Cu at higher ion fluences. These experimental results from Raman spectroscopy were also consistent with the XRD analysis, which also showed the presence of mixed phases of CuO, Cu2O, and Cu. Results from AFM showed that the value of average roughness increased due to more defects. DRS results revealed the variation in band-gap energy for pristine and implanted samples from 1.96 to 1.71 eV. Density functional theory (DFT) simulations confirmed that Ag ion implantation causes the reduction of CuO surface into Cu2O and Cu. We found that Ag ion implantation-induced defects lead to the mixed phases of CuO, Cu2O, and Cu, which can help in the selective sensing of ethanol and acetone, demonstrating this as a useful technique and having potential applications in energy conversions, and gas and biomolecule sensing.

Effect of Cu, Zn and Ag Ion Implantation on the Surface Modification of Bacterial Cellulose Films

The paper presents the preliminary results of cellulose modification by ion implantation. Three types of ions were implanted, i.e., copper, zinc and silver with fluences of 5 × 1014 and 5 × 1015 cm−2, respectively. The acceleration voltage of the implanted ions was 30 kV. The ion penetration depth profiles showed differences, especially in the Cu and Ag cases, due to the different ion beams of these elements. The implantation of cellulose with ions clearly changed the wettability of the material surface in the direction of hydrophobicity. The impact of implantation on the growth of the cellulose surface by mold fungi was also noticeable. Only the silver ion implantation had a negative effect on the growth of the Trichoderma viride fungus but did not cause a complete inhibition of growth. Cellulose implantation with Cu and Zn ions clearly stimulated the growth of fungi on the surface of the polymer.

The Effect of 600 keV Ag Ion Irradiation on the Structural, Optical, and Photovoltaic Properties of MAPbBr3 Films for Perovksite Solar Cell Applications.

A competitive new technology, organic metallic halide perovskite solar cells feature a wide working area, low manufacturing costs, a long lifespan, and a significant amount of large efficacy of power conversion (PCE). The spin-coating technique was utilized for the fabrication of pure CH3NH3PbBr3 (MAPbBr3) thin films, and these films are implanted with 600 keV silver (Ag) ions at fluency rate of 6 × 1014 and 4 × 1014 ions/cm2. XRD analysis confirmed the cubic structure of MAPbBr3. A high grain size was observed at the fluency rate of 4 × 1014 ions/cm2. The UV-Vis spectroscopic technique was used to calculate the optical properties such as the bandgap energy (Eg), refractive index (n), extinction coefficients (k), and dielectric constant. A direct Eg of 2.44 eV was measured for the pristine film sample, whereas 2.32 and 2.36 eV were measured for Ag ion-implanted films with a 4 × 1014 and 6 × 1014 ions/cm2 fluence rate, respectively. The solar cells of these films were fabricated. The Jsc was 6.69 mA/cm2, FF was 0.80, Voc was 1.1 V, and the efficiency was 5.87% for the pristine MAPbBr3-based cell. All of these parameters were improved by Ag ion implantation. The maximum values were observed at a fluency rate of 4 × 1014 ions/cm2, where the Voc was 1.13 V, FF was 0.75, Jsc was 8.18 mA/cm2, and the efficiency was 7.01%.

Machine learning prediction of 2D perovskite photovoltaics and interaction with energetic ion implantation

Atomic-level prediction combined with machine learning (ML) and density functional theory (DFT) is carried out to accelerate the fast discovery of potential photovoltaics from the 2D perovskites. Based on the ML prediction, stability test, optical absorption, and the theoretical power conversion efficiency (PCE) evaluation, two promising photovoltaics, i.e., Sr2VON3 and Ba2VON3, are discovered with PCE as high as 30.35% and 26.03%, respectively. Cu, Ag, C, N, H, and He ion implantation are adopted to improve the photovoltaic performance of the high-efficiency and best stable perovskite Sr2VON3. The time-dependent DFT electronic stopping calculations for energetic ion implanted Sr2VON3 indicate that the excited electrons from the valence band contribute to the electron–phonon coupling, the evolution and formation of the defects, and the photovoltaic performance. This work opens the way to the high-accuracy fast discovery of the high-efficiency and environmentally stable 2D perovskites solar cells and the further engineering improvement in photovoltaic performance by ion implantation.

Influence of Ag/Ca ratio on the osteoblast growth and antibacterial activity of TiN coatings on Ti-6Al-4V by Ag and Ca ion implantation

Titanium nitride (TiN) coating has many prominent properties such as chemical stability, high hardness, excellent wear properties, biocompatibility and so on, which make it as a potential candidate for inhibiting the release of toxic ions and improving mechanical properties of dental and orthopedic implants made by titanium‑aluminum‑vanadium (Ti-6Al-4V). Of course, the biologically inert and poor antibacterial property of TiN limits its application. In this work, TiN coating was firstly deposited on the surface of Ti-6Al-4V substrate to inhibit its toxic ions release. Then, silver (Ag) and calcium (Ca) with different ratios were implanted into TiN coatings by plasma immersion ion implantation and deposition (PIII&D) system to enhance both osteoblast growth and antibacterial activity on the surfaces of TiN coatings. The results show that TiN coating inhibits the release of toxic ions such as Al and V. X-ray photoelectron spectrometer (XPS) and X-ray diffraction (XRD) analyses proved the presence of Ag, Ca on the surface of Ag and Ca implanted TiN (Ag/Ca-TiN). Scanning electron microscopy (SEM) was used to observe the surfaces' morphologies of samples, which takes advantage of distinct detectors to visualize secondary and back-scattering electrons. The protein adsorption experiment showed that the protein adsorption capacities increased with the increase of Ca ratio. When the results of antibacterial and cell adhesion tests were combined, Ag/Ca(2:1)-TiN indicated the best osteoblast adhesion and antibacterial activity in vitro due to the synergistic effect of Ag and Ca. The improved inhibiting ability in releasing toxic ions, osteoblast adhesion and antibacterial activity of the Ag/Ca(2:1)-TiN suggest that it might be a potential choice for surface medication of orthopedic implants clinically.

Control of optical absorption of silica glass by Ag ion implantation and subsequent heavy ion irradiation

Silica glass samples were implanted with 50–380 keV Ag ions. After ion implantation, some samples were subsequently irradiated with 16 MeV Au ions. The effects of the implantation and the subsequent Au ion irradiation on the optical absorption spectra and morphologies of the Ag nanoparticles produced in the samples were studied by using an ultraviolet–visible scanning spectrophotometer and a transmission electron microscope, respectively. For the samples implanted with 200 keV or 380 keV Ag ions to high fluence, optical absorption peaks appeared around 600 nm, as well as the well-known surface plasmon resonance peaks around 400 nm, and Ag spherical nanoparticles with a high spatial density were observed. The absorption peaks around 600 nm are explained as being due to interactions between the Ag nanoparticles (inter-particle interaction). Under the subsequent irradiation with 16 MeV Au ions, the optical absorption around 400 and 600 nm showed a blue shift and the peak intensity markedly decreased. Transmission electron microscopy observation revealed an elongation of the Ag nanoparticles along the direction of the 16 MeV Au irradiation, and a resulting enlargement of the distances between the nanoparticles. The change in the peak wavelength and peak intensity of the optical absorption by the 16 MeV Au irradiation can, therefore, be explained as originating from a decrease in inter-particle interaction.

Ion beam synthesis of Au-Ag alloy nanoparticles in TiN thin films

Formation of Au-Ag alloy nanoparticles in TiN thin films is demonstrated through sequential implantation of Au and Ag ions. The irradiations were done with 200 keV Au ions at fluence of 1.0 × 1016 ions/cm2 and 150 keV Ag ions to the fluences in the range of 0.7–1.3 × 1017 ions/cm2. It was found that irradiations introduce around 1.5 at.% of gold and up to ~20 at.% of silver species causing also the significant sputtering of the surface. TiN surface besides the topographic undergoes chemical changes. The presence of silver and gold is confirmed by photoemission spectroscopy showing that the implanted ions did not form any kind of compound with the surrounding matrix. Electron microscopy evidenced the formation of crystalline and quasi-spherical particles with dimensions below 10 nm. Elemental analysis revealed that the obtained nanoparticles present Au-Ag alloys, with two elements mixed over the whole volume of the particles in different Au:Ag ratios.

Fused Silica with Embedded 2D‐Like Ag Nanoparticle Monolayer: Tunable Saturable Absorbers by Interparticle Spacing Manipulation

AbstractSaturable absorbers are key elements for generation of ultrafast laser pulses. The commercially available semiconductor saturable absorber mirrors are wavelength sensitive and with complex fabrication process and high cost. Fused silica is one of the basic materials for various optical applications. Plasmonic nanoparticles can be used to efficiently modulate the optical properties of dielectric materials owing to the enhanced field effects based on localized surface plasmonic resonance. Ion implantation is a direct technique to synthesize plasmonic nanoparticles inside dielectric materials, which can simultaneously tailor the optical nonlinearity of substrates significantly. In this work, Ag ion implantation into fused silica with tunable interparticle spacing is used to generate broadband optical nonlinearities and to endow silica with ultrafast saturable absorption property. This ion implantation forms a 2D‐like Ag nanoparticle monolayer buried inside fused silica wafer. The fused silica with embedded 2D‐like Ag nanoparticle monolayer is further applied as a new saturable absorber to generate ultrafast laser pulses with pulse duration of 27 ps and repetition rate of 6.5 GHz through the passive mode‐locking process. This work opens up a new route to develop low‐cost, highly stable saturable absorbers, and offers the possibility to build novel silica‐based photonic systems through nanoparticle spacing manipulation.

Importance of the volume fraction and particle density of Ag nanoparticles to the coupling process of relief-type Ag/SiO2 nanocomposite grating coupler

600-nm-periodic relief-type SiO2 grating coupler and Ag/SiO2 nanocomposite grating coupler are fabricated by separately etching the SiO2 waveguide slabs before and after low-energy Ag ion implantation, and their vertical input coupling efficiencies (VICEs) as well as that of Ag/SiO2 nanocomposite grating coupler after 600 °C anneal in flowing nitrogen are investigated by means of the transmission spectroscopy. Our results clearly demonstrate that owing to the introduction of Ag nanoparticles (NPs), the Ag/SiO2 nanocomposite grating coupler is more efficient to couple the incident light beams in a wavelength range of 620–880 nm into the SiO2 waveguide layer than the SiO2 grating coupler. Especially, our results also demonstrate that 600 °C anneal can bring about a decrease in VICE of Ag/SiO2 nanocomposite grating coupler. Further discussions reveal that the anneal-induced decrease in VICE of Ag/SiO2 nanocomposite grating coupler is due to the decreased refractivity of Ag/SiO2 nanocomposite teeth in a wavelength range of 620–880 nm because of the reduction in volume fraction of Ag NPs and the lowered reflectivity of Ag/SiO2 nanocomposite teeth in the same wavelength range because of the decline in particle density of Ag NPs. The above findings substantially indicate the particular importance of the volume fraction and particle density of Ag NPs to the coupling process. In our opinion, the volume fraction and particle density of Ag NPs are probably improved by suppressing the sputtering loss of Ag implants, and thereby, we can have a chance to fabricate a thin but efficient Ag/SiO2 coupler in the future, which might be useful for the development of large-scale photonic integrated circuits.

Nanometer-Scale Surface Structure and Sterilization Characteristics of Na/Ag Ion-Exchanged Glass for Anti-Biofouling Application.

Most objects and structures exposed to a marine environment for more than a month undergo biofouling of the surface. Biofouling is a phenomenon in which micro-organisms attach to marine structures and may result in deterioration of the structure or breakage of the structure due to weight gain. In this study, glass, which can inhibit biofouling of marine structures, was prepared and its germicidal properties were analyzed. For this purpose, Ag ions were implanted into soda-lime-silicate glass by the ion-exchange method. For the glass immersed in seawater, the bactericidal effect of the glass specimen was than evaluated by inoculating the strain and counting the number of viable cells after 12 or 24 h. Experimental variables were ion exchange conditions, time immersed in seawater, and time spent inoculating the strain. In particular, the surface state of the ion exchange glass before and after immersion in seawater was observed at the nanometer level, and the elution amount of Ag ions with time was measured by the ICP mass analysis method. As the ion exchange time increased, the amount of ion exchange increased. The amount of ions was consistent with Fick's first law, which is proportional to the square root of time. When ion-exchanged specimens were immersed in seawater, the amount of Ag ions eluted was on the order of ppm. Si and Na ions were also eluted from the glass. As the ion exchange time increased, crystals of 60~80 nm, which are presumed to be Na₂CO₃ phase, formed densely on the surface of the specimen. However, when the glass specimens were immersed in seawater, crystals formed on the surface dissolved and disappeared. Cracks subsequently formed on the surface and finally the surface collapsed. After 30 days, a fresh glass surface appeared again. This is a very interesting result because it shows that the reaction between glass and seawater is very similar to that between aqueous solutions. When the glass implanted with Ag ions is immersed in seawater, the surface dissolves and the glass-network-structure collapses, resulting in considerable Ag ion elution, which enhances bactericidal action in seawater. For example, when a specimen immersed in seawater for 30 days was inoculated with the strain for 24 hours, the number of strains decreased from 2.1 × 106 cells/ml to 0 cell/ml, indicating 100% disinfection ability. In this study, soda-lime-silicate glass with Ag ion implantation by the Na/Ag ion exchange method showed an excellent germicidal effect when in contact with sea water. From this result, it can be expected that long-term marine biological pollution can be suppressed by applying the glass developed in this research to marine structures.

Investigation of silver nanoparticles on titanium surface created by ion implantation technology.

Objectives: Using dental Ti implants has become a well-accepted and used method for replacing missing dentition. It has become evident that in many cases peri-implant inflammation develops. The objective was to create and evaluate the antibacterial effect of silver nanoparticle (Ag-NP) coated Ti surfaces that can help to prevent such processes if applied on the surface of dental implants.Methods: Annealing I, Ag ion implantation by the beam of an Electron Cyclotron Resonance Ion Source (ECRIS), Ag Physical Vapor Deposition (PVD), Annealing II procedures were used, respectively, to create a safely anchored Ag-NP layer on 1x1 cm2 Grade 2 titanium samples. The antibacterial effect was evaluated by culturing Staphylococcus aureus (ATCC 29213) on the surfaces of the samples for 8 hours, and comparing the results to that of glass as control and of pure titanium samples. Alamar Blue assay was carried out to check cytotoxicity.Results: It was proved that silver nanoparticles were present on the treated surfaces. The average diameter of the particles was 58 nm, with a 25 nm deviation and Gaussian distribution, the the filling factor was 25%. Antibacterial evaluation revealed that the nanoparticle covered samples had an antibacterial effect of 64.6% that was statistically significant. Tests also proved that the nanoparticles are safely anchored to the titanium surface and are not cytotoxic.Conclusion: Creating a silver nanoparticle layer can be an option to add antibacterial features to the implant surface and to help in the prevention of peri-implant inflammatory processes. Recent studies demonstrated that silver nanoparticles can induce pathology in mammal cells, thus safe fixation of the particles is essential to prevent them from getting into the circulation.

Synthesis of AuAg@Ag core/shell bimetallic nanoparticles in titanium nitride thin films by sequential ion implantation

In this study, we demonstrated the formation of a new type of AuAg@Ag nanostructure in titanium nitride (TiN) thin films using sequential implantation of Au and Ag ions. The TiN films deposited by DC reactive sputtering were sequentially implanted with 200 keV gold ions at fluences of 0.5 × 1016 and 1 × 1016 ions/cm2 and 150 keV silver ions at fluences of 1 × 1016, 2 × 1016, 3 × 1016, and 4 × 1016 ions/cm2. Formation of spherical-like particles with dimensions below 10 nm, homogeneously distributed along the ion track of implanted ions is verified by high resolution transmission electron microscopy. Specific nanostructure containing AuAg alloy in the center of the particle and only silver on the periphery was found in the TiN sample sequentially implanted with 1.0 × 1016 ions/cm2 of Au and 4 × 1016 ions/cm2 of Ag using high angle annular dark field scanning electron microscopy together with elemental mapping analysis. On the other hand, for the sample implanted with 0.5 × 1016 ions/cm2 of Au and 4 × 1016 ions/cm2 of Ag only formation of AuAg alloy was observed. A mechanism for the formation of a new type core/shell nanostructure in ion implanted TiN thin films is proposed. By varying the implantation fluence of the gold and silver ions properly, the optimized experimental parameters for creation of a specific AuAg@Ag core/shell nanoparticles were achieved.

Ag nanoparticles embedded in Nd:YAG crystals irradiated with tilted beam of 200 MeV Xe ions: optical dichroism correlated to particle reshaping

We report on the fabrication of reshaped Ag nanoparticles (NPs) embedded in a Nd:YAG crystal by combining Ag ion implantation and swift heavy Xe ion irradiation. The localized surface plasmon resonance (LSPR) effect is proved to be efficiently modulated according to the phenomenon of polarization-dependent absorption. The LSPR peak located at 448 nm shows red shift and blue shift at 0° and 90° polarization, respectively, which is in good agreement with calculation by discrete dipole approximation. Based on the near-field intensity distribution, the interaction between reshaped NPs shows a non-ignorable effect on the optical absorption. Furthermore, the polarization-dependence of the photoluminescence (PL) intensity is analyzed, which is positively related to the modulated LSPR absorption. It demonstrates the potential of the enhancement of PL intensity by embedded plasmonic Ag NPs. This work breaks the conventional view of the quenching effect of NPs by ion irradiation and opens a new way to realize the modulation of optical dichroism.

Optical characterization of the HgCdTe-based composite structure obtained by Ag ion implantation

The results concerning the formation of nano-scale patterns on the surface of a ternary compound are presented. The evolution of surface morphology of (111) Hg1−xCdxTe (MCT) (х ~ 0.223) epilayers due to ion irradiation in the energy range of 100–140 keV was studied. Modification of the surface was performed using the method of normal (θ = 0°) and oblique—incidence (θ = 45°) bombardment by Ag+ ions. Surface characteristics were investigated using atomic force microscopy and X-ray photoelectron spectroscopy techniques. Low-temperature photoluminescence and Raman spectroscopy were used for the investigation of the recombination and vibrational properties as well as the defect-impurity states of as-grown and implanted Hg0.777Cd0.223Te epilayers. It was found that ion beam structured regions of MCT surface demonstrate photoluminescence emission in the range of 500–850 nm, with intense peaks at around 733 nm (1.69 eV) and 570 nm (2.16 eV) with a long-wavelength shoulder at 620 nm (2 eV). The observed emission lines are suggested to be mainly related to the presence of various point defects in oxide phases (CdO and Ag2O) induced by ion bombarding in the base material (HgCdTe).

Structural and optical investigations of 120 keV Ag ion implanted ZnO thin films

Structural as well as optical modifications in zinc oxide (ZnO) thin film with Ag ion implantation were carried out in the present study. The pure ZnO thin films were synthesized by RF-magnetron sputtering technique at room temperature. 120 keV Ag ion beam was used for Ag ion implantation with different implantation dose from 3 × 1014 to 3 × 1016 ions/cm2 by negative ion implantation facility. The thickness and composition of pure ZnO and Ag implanted film at higher dose 3 × 1016 ions/cm2 were estimated by Rutherford backscattering spectroscopy. The change in surface stoichiometry was estimated by using X-ray photoelectron spectroscopy with Ag ion implantation. The modifications in structural features with Ag ion implantation in ZnO films were observed by X-ray diffraction technique (XRD). The pure ZnO thin film was preferentially grown in c-axis direction with crystallite size ~10.6 nm confirmed by XRD. Surface morphology of the pure and Ag implanted ZnO thin films was estimated by atomic force microscopy and revealed the roughness and grain size were increased with increasing the implantation dose. The transmittance of the films was decreased drastically at higher implantation dose as corroborated by UV–visible spectroscopy. Raman spectroscopy of the films was used to understand the lattice defects and disordering during Ag ion implantation. At the higher dose, the film was entirely oriented in c-axis confirmed by X-ray pattern, which can be beneficial for device fabrication.

Evolution of structural and optical properties of Ag implanted CrN thin films with annealing temperature

This study reports on the changes of the structural and optical properties occurring in CrN thin films upon Ag ion implantation. The films were grown by reactive sputtering on top of Si (100) wafers at a temperature of around 150 °C. Subsequently, the films were implanted with Ag ion fluences in the range of 0.5 × 1016 ions/cm2 ‒ 2 × 1016 ions/cm2 with energy of 200 keV. The structural and morphological changes, promoted by in-vacuum annealing of the as-implanted thin films at 200 °C, 400 °C and 700 °C, resulted in different optical responses of the CrN:Ag films due to the formation of Ag nanoparticles. The nanoparticles were inhomogenously distributed through the layer, which is related to the implantation distribution of silver in CrN. Apart from this, Ag nanoparticles with a size of 20–25 nm were formed at the surface of the layer. These structural properties are responsible for the formation of a broad optical absorption peak. This peak is located at ∼420 nm and can be associated with the plasmon resonance of Ag particles embedded in the CrN matrix.

Ag implantation-induced modification of Ni–Ti shape memory alloy thin films

ABSTRACTNanocrystalline thin films of Ni–Ti shape memory alloy are deposited on an Si substrate by the DC-magnetron co-sputtering technique and 120 keV Ag ions are implanted at different fluences. The thickness and composition of the pristine films are determined by Rutherford Backscattering Spectrometry (RBS). X-Ray diffraction (XRD), atomic force microscopy (AFM) and four-point probe resistivity methods have been used to study the structural, morphological and electrical transport properties. XRD analysis has revealed the existence of martensitic and austenite phases in the pristine film and also evidenced the structural changes in Ag-implanted Ni–Ti films at different fluences. AFM studies have revealed that surface roughness and grain size of Ni–Ti films have decreased with an increase in ion fluence. The modifications in the mechanical behaviour of implanted Ni–Ti films w.r.t pristine film is determined by using a Nano-indentation tester at room temperature. Higher hardness and the ratio of higher hardness (H) to elastic modulus (Er) are observed for the film implanted at an optimized fluence of 9 × 1015 ions/cm2. This improvement in mechanical behaviour could be understood in terms of grain refinement and dislocation induced by the Ag ion implantation in the Ni–Ti thin films.

Enhancement of thermoelectric power of PbTe thin films by Ag ion implantation

Enhancement of the figure of merit (ZT) of thermoelectric materials is the topic of current research in energy studies. We report an enhancement in the thermoelectric power (TEP) of thermally evaporated PbTe thin films by low energy Ag ion implantation. This implantation results in PbTe:Ag nanocomposites. Implantations were carried out at a 130 keV Ag ion beam with ion fluences of 3 × 1015, 1.5 × 1016, 3 × 1016, and 4.5 × 1016 ions/cm2. The atomic concentrations were determined using Rutherford backscattering and found to be 1 at. %, 5 at. %, 10 at. %, and 14 at. % in the implanted PbTe films. Scanning electron microscopy images show the presence of fine cracks on the surface of as-deposited PbTe thin films that get shortened and suppressed and finally disappear at higher fluences of Ag ion implantation. The TEP measurements, from 300 K to 400 K, show ∼25% enhancement in the Seebeck coefficient of the Ag ion implanted films in comparison to the pristine PbTe thin film. The synchrotron based high resolution X-ray diffraction and X-ray photoelectron spectroscopy investigations reveal the formation of Ag2Te in the surface layer after Ag ion implantation.

Enhancement of Ag nanoparticles concentration by prior ion implantation

Thermally grown SiO2 layer on Si substrates were singly or sequentially implanted with Zn or Cu and Ag ions at the same fluence of 2×1016/cm2. The profiles of implanted species, structure, and spatial distribution of the formed nanoparticles (NPs) have been characterized by the cross-sectional transmission electron microscope (XTEM) and Rutherford backscattering spectrometry (RBS). It is found that pre-implantation of Zn or Cu ions could suppress the self sputtering of Ag atoms during post Ag ion implantation, which gives rise to fabrication of Ag NPs with a high density. Moreover, it has also been demonstrated that the suppressing effect strongly depends on the applied energy and mobility of pre-implanted ions. The possible mechanism for the enhanced Ag NPs concentration has been discussed in combination with SRIM simulations. Both vacancy-like defects acting as the increased nucleation sites for Ag NPs and a high diffusivity of prior implanted ions in SiO2 play key roles in enhancing the deposition of Ag implants.