Magnetron Sputtering Deposition Research Articles

High-Power Impulse Magnetron Sputter Deposition of Ag on Self-Assembled Au Nanoparticle Arrays at Low-Temperature Dewetting Conditions.

Plasmons have facilitated diverse analytical applications due to the boosting signal detectability by hot spots. In practical applications, it is crucial to fabricate straightforward, large-scale, and reproducible plasmonic substrates. Dewetting treatment, via applying direct thermal annealing of metal films, has been used as a straightforward method in the fabrication of such plasmonic nanostructures. However, tailoring the evolution of the dewetting process of metal films poses considerable experimental complexities, mainly due to nanoscale structure formation. Here, we use grazing-incidence small- and wide-angle X-ray scattering for the in situ investigation of the high-power impulse magnetron sputter deposition of Ag on self-assembled Au nanoparticle arrays at low-temperature dewetting conditions. This approach allows us to examine both the direct formation of binary Au/Ag nanostructure and the consequential impact of the dewetting process on the spatial arrangement of the bimetallic nanoparticles. It is observed that the dewetting at 100 °C is sufficient to favor the establishment of a homogenized structural configuration of bimetallic nanostructures, which is beneficial for localized surface plasmon resonances (LSPRs). The fabricated metal nanostructures show potential application for the surface-enhanced Raman scattering (SERS) detection of rhodamine 6G molecules. As SERS platform, bimetallic nanostructures formed with dewetting conditions turn out to be superior to those without dewetting conditions. The method in this work is envisioned as a facile strategy for the fabrication of plasmonic nanostructures.

Tailored Nanocones Arrays on Cellulose Fiber: A Higher-Performance Flexible SERS Substrate for Trace Chemical Detection

This study presents the successful fabrication of silver nanocone surface-enhanced Raman spectroscopy (SERS) substrate on flexible 70 GSM paper using the Direct Current (DC) magnetron sputter deposition technique. XRD analysis confirmed the crystalline nature and face-centered cubic structure of the Silver Nanocone (AgNC) substrate. SEM analysis revealed the fabricated AgNC substrate shows nanocones arrayed on the cellulose fibers. UV-visible spectral analysis validates the surface plasmon resonance peak of the AgNC substrate at 406 nm. Furthermore, SERS spectral analysis showed excellent detection abilities by accurately identifying rhodamine 6G and methylene blue dyes and fipronil pesticides at concentrations of 10−9 M, 10−8 M, and 10−6 M respectively. In addition, the substrate detects fipronil (pesticide) sprayed on tomatoes and nicotine (energy booster) mixed with tea for commercial applications. The substrate exhibits enhancement factor values for rhodamine 6G, methylene blue, fipronil, and nicotine as 1.3×107, 1.2×106, 2.6×105, and 5.8×104, respectively. Theoretical validation using density functional theory confirms the experimental Raman and SERS peaks show good similarity. Considering that the charge transfer mechanism shown in the study of the frontier molecular orbitals allowed for the identification of the interaction between the analyte molecules and silver cluster. The fabricated SERS substrate exhibited remarkable stability and reproducibility.

Tailored nanocones arrays on cellulose fiber: A higher-performance flexible SERS substrate for trace chemical detection

This study presents the successful fabrication of silver nanocone surface-enhanced Raman spectroscopy (SERS) substrate on flexible 70 GSM paper using the Direct Current (DC) magnetron sputter deposition technique. XRD analysis confirmed the crystalline nature and face-centered cubic structure of the Silver Nanocone (AgNC) substrate. SEM analysis revealed the fabricated AgNC substrate shows nanocones arrayed on the cellulose fibers. UV–visible spectral analysis validates the surface plasmon resonance peak of the AgNC substrate at 406 nm. Furthermore, SERS spectral analysis showed excellent detection abilities by accurately identifying rhodamine 6G and methylene blue dyes and fipronil pesticides at concentrations of 10−9 M, 10−8 M, and 10−6 M respectively. In addition, the substrate detects fipronil (pesticide) sprayed on tomatoes and nicotine (energy booster) mixed with tea for commercial applications. The substrate exhibits enhancement factor values for rhodamine 6G, methylene blue, fipronil, and nicotine as 1.3 × 107, 1.2 × 106, 2.6 × 105, and 5.8 × 104, respectively. Theoretical validation using density functional theory confirms the experimental Raman and SERS peaks show good similarity. Considering that the charge transfer mechanism shown in the study of the frontier molecular orbitals allowed for the identification of the interaction between the analyte molecules and silver cluster. The fabricated SERS substrate exhibited remarkable stability and reproducibility.

In-situ optimization of lateral film uniformity in PVD system by using Fiber Bragg grating temperature sensors

Fiber Bragg grating (FBG) based temperature sensing method has been employed in this work for measuring the lateral temperature distribution on substrate plane during pulse DC magnetron sputtering deposition for optimization of lateral film uniformity. The evolution of temperature distribution with the variation of important process parameters like pulse width (496–1616 ns), deposition pressure (3.1 × 10−3–1.9 × 10–2 mbar) and sputtering power (25–250 W) have been measured over 40 mm radial distance on glass substrate horizon. To investigate the effect of substrate height on the temperature distribution, the later has been measured at two different substrate heights (60 mm and 90 mm) for varying sputtering power. Finally, the effect of variation in temperature distribution on uniformity of thickness and optical, morphological and structural properties have been investigated by separately depositing two HfO2 thin films at two representative extreme deposition powers (75 W and 200 W). The correlation of film non-uniformity of the above properties with the temperature distribution suggests that FBG based multipoint temperature sensing can be possibly used as an indicative tool for in situ optimization of the lateral film uniformity. In addition, the fast response and workability in plasma environment of FBG sensors enables precise in situ mapping of temperature distribution in sputtering process.

Photocatalytic CO2 reduction to CH4 in continuous flow reactor using Fe2TiO5 enhanced by magnetron sputtering-deposited CuO nanoparticles cocatalyst

Fe2TiO5 is a promising and underexplored material as a semiconductor photocatalyst for CO2 reduction reaction (PCO2RR), aimed at mitigating greenhouse gas emissions. In this study, pure Fe2TiO5 was synthesized via solvothermal method and subsequently calcined across temperatures ranging from 600 to 900 °C. The performance was evaluated within a PCO2RR under simulated sunlight, generating CH4 as a single detectable product. Further enhancement was achieved by depositing CuO nanoparticles below 5 nm onto the Fe2TiO5 surface using magnetron sputtering deposition. The yield of CH4 increased from 0.032 to 0.042 µmol. As far as we know, this marks the inaugural application of Fe2TiO5 as a photocatalyst for CO2 reduction.

Superhydrophobic synergistic antibacterial ZrO2-based surfaces with tertiary hierarchical structures fabricated by femtosecond laser texturing and surface modification

Zirconia (ZrO2) is a hard and brittle dental implant material without anti-infective property. This work reports the preparation of a tertiary micro-nano hierarchical structure on a ZrO2 surface via femtosecond laser texturing combined with magnetron sputtering deposition of an Ag layer (Ag/ZrO2), aiming to achieve a superhydrophobic synergistic antibacterial effect. Laser-scanning pitch and Ag layer thickness were systematically optimized for obtaining the tertiary hierarchical structure. The wettabilities, antibacterial properties and durabilities of various ZrO2 and stearic acid modified Ag/ZrO2 (S-Ag/ZrO2) surfaces were further tested and comparatively analyzed. The results revealed that the optimal process parameters were a laser-scanning pitch of 30 μm and an Ag layer thickness of 100 nm. The as-obtained S-Ag/ZrO2 sample displayed a tertiary micro-nano hierarchical structure, which was featured by a periodic regular conical micro-convex structure covered with ZrO2 nano-protrusions and Ag nanoparticles. This structure could not only greatly reduce the solid-liquid contact area to achieve outstanding superhydrophobicity and durability, it could also sustainably release bacteria-killing Ag+ to obtain an antibacterial ratio of 95.1 % and ensure a long-term antibacterial effect. In addition, the optimal S-Ag/ZrO2 sample having this structure showed a PC12 cell survival rate of up to 81.75 %, demonstrating its good biocompatibility. This work may be of great inspiration and reference for the expansion of the use of ZrO2 in dentistry.

Two-step process for the fabrication of direct FLG\\MoS2 heterostructures

MoS2 has proven its efficacy in flexible electronics, transistor devices, and various biological and chemical applications. However, it is still challenging to achieve large-area MoS2 monolayers with desired material quality and electrical properties to fulfill the requirement for practical applications. Moreover, the main strategy for the preparation of a 2D heterostructure it is based on the sequential stacking of the layered materials using wet or dry transfer methods which introduces many defects. This paper presents an economically viable and straightforward two-step methodology to obtain MoS2 thin films, encompassing magnetron sputtering deposition of Mo and subsequent annealing in a sulfur-rich environment. This approach successfully yielded MoS2 thin films on Si\\SiO2 substrates. Additionally, heterostructures consisting of few layer graphene (FLG) and MoS2 were directly obtained using the same method. The utilization of grazing incidence X-ray diffraction verified the formation of the hexagonal MoS2 phase, a finding further confirmed by Raman spectroscopy. X-ray photoelectron spectroscopy (XPS) investigations revealed the successful sulfurization process, with surface-bound oxides forming only subsequent to air exposure. Comprehensive assessment involving X-ray reflectivity, atomic force microscopy and XPS collectively inferred the fabrication of thin films comprised of a small number of MoS2 layers covering the entire substrate. Electrical assessments exhibited an electrical hysteresis, demonstrating its potential for memristor applications. Overall, this study outlines a cost-effective fabrication method for producing nanoscale MoS2 thin films with excellent properties, avoiding the use of toxic gases such as H2S. These findings contribute to the potential development of cutting-edge applications.

Reactive Magnetron Sputtering for Y-Doped Barium Zirconate Electrolyte Deposition in a Complete Protonic Ceramic Fuel Cell

Yttrium-doped barium zirconate is a commonly used electrolyte material for Protonic Ceramic Fuel Cells (PCFC) due to its high protonic conductivity and high chemical stability. However, it is also known for its poor sinterability and poor grain boundary conductivity. In this work, in response to these issues, reactive magnetron sputtering was strategically chosen as the electrolyte deposition technique. This method allows the creation of a 4 µm tick electrolyte with a dense columnar microstructure. Notably, this technique is not widely utilized in PCFC fabrication. In this study, a complete cell is elaborated without exceeding a sintering temperature of 1350 °C. Tape casting is used for the anode, and spray coating is used for the cathode. The material of interest is yttrium-doped barium zirconate with the formula BaZr0.8Y0.2O3−δ (BZY). The anode consists of a NiO-BZY cermet, while the cathode is composed of BZY and Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSFC) in a 50:50 weight ratio. The electrochemical impedance spectroscopy analysis reveals a global polarization resistance of 0.3 Ω cm2, indicating highly efficient interfaces between electrolytes and electrodes.

Optimizing the Thickness Uniformity of Magnetron Sputtering Deposited Films on a Large-Scale Curved Workpiece Surface

This study prepared magnetron-sputtering deposition film on a large-scale curved workpiece with a favorable thickness uniformity using a rectangular target cathode. For a substrate rotation structure with eccentric rotation/revolution composite motion, the geometrical model of the thickness distribution of the coating film on a large substrate was established in combination with the principle of rectangular cathode magnetron sputtering. The integral formula of the film thickness was derived, and various film thickness distribution patterns under different parameters were simulated. According to the present research results, the film thickness distribution can be optimized by adjusting the revolution-to-rotation radius and eccentric ratios. At an eccentric distance of 400 mm and a radius ratio of 2.78, the most favorable uniformity degree of 0.87 was obtained, which was controlled by the motion path of the fixed point on the substrate. The proposed approach helps to obtain large-scale films with favorable uniformity on the substrate.

Unlocking dual-band electrochromism with stacked structure of amorphous tungsten oxide and Prussian blue

Dual-band electrochromic smart windows can selectively regulate the transmittance of visible and near-infrared (NIR) light, thereby significantly reducing energy consumption in buildings. However, the selective regulation for visible and NIR regions often relies on the integration of multiple components, together with meticulous design and fabrication. Herein, we propose the stacking of amorphous tungsten oxide (a-WO3) on the surface of Prussian blue (PB) through a straightforward magnetron sputtering deposition. Benefiting from the numerous voids-containing structures in the microstructure of a-WO3 films, the stacking structures are conducive to the insertion and transport of electrolyte ions, ensuring the electrochemical activity and electrochromic performance of the inner PB layer. The prepared PB/WO3 bilayer thin film can achieve three functionality modes in dual-band electrochromism: “bright”, “warm”, and “dark”, with high optical modulation of 74.9 % at 700 nm and 80.3 % at 1300 nm, respectively. Additionally, they demonstrate fast coloring/bleaching response (2.9/7.6 s at 700 nm and 6.0/6.2 s at 1300 nm) and satisfying cycling stability (retaining 95.3 % of its initial modulation after 500 cycles). The bilayer thin films based on amorphous electrochromic materials with an intrinsic abundance of voids-containing structures introduce a novel approach to the independent dual-band modulation for demanded light/thermal control.

Investigation of crystalline and band alignment properties of NiO/GaN and Ni0.5Co0.5O/GaN heterojunctions using synchrotron radiation based techniques

Epitaxial layers of NiO and Ni0.5Co0.5O have been deposited on GaN templates using RF magnetron sputtering deposition technique. The epitaxial relationship in out-of-plane and in-plane directions for NiO and Ni0.5Co0.5O layers with respect to GaN is [111]NiO(Ni0.5Co0.5O)∥[0001]GaN and [1̅10]NiO(Ni0.5Co0.5O)∥[1̅21̅0]GaN, respectively. The epi-layers are found to have two triangular domain structures oriented along [111] direction with an in-plane rotation of 60° with respect to each other. Photoelectron spectroscopy (PES) has been used to determine the valence band offset (∆EV) and the band alignment at the heterojunctions (HJs). The ∆EV at NiO/GaN and Ni0.5Co0.5O/GaN HJs are 1.2 ± 0.2 eV and 1.8 ± 0.2 eV, respectively. The conduction band offsets (∆EC) have also been estimated using the determined values of optical band gap (NiO: Eg = ∼ 3.5 eV; Ni0.5Co0.5O: Eg = ∼ 3.3 eV) from optical transmission measurements. The values of ∆EC are found to be 1.5 ± 0.2 eV and 1.9 ± 0.2 eV at NiO/GaN and Ni0.5Co0.5O/GaN HJs, respectively. A type-II band alignment is observed at both the HJs. Higher values of valence band and conduction band offsets are observed at Ni0.5Co0.5O/GaN HJ in comparison to NiO/GaN. These experimentally determined values of band offsets can be used to design wide band gap HJ based devices like photodetectors, where higher values of band off-set at the Ni0.5Co0.5O/GaN HJ can be utilized to confine the carriers.

The effects of crystal orientation on the ferroelectric and optoelectronic properties of Pt/Na0.5Bi0.5TiO3/La0.5Sr0.5CoO3 heterostructures

Due to their excellent ferroelectric, semiconducting, and optoelectronic properties, perovskite ferroelectric thin films have attracted increasing attention in the photovoltaic field. Using La0.5Sr0.5CoO3 (LSCO) as the bottom electrode, flake, strip and pyramidal Na0.5Bi0.5TiO3 (NBT) films were prepared on (001), (110) and (111) SrTiO3 (STO) substrates by off-axis magnetron sputtering and pulsed laser deposition, respectively. XRD and Phi scan results show that both LSCO and NBT are perovskite structures and satisfy the epitaxial growth along the substrate STO. NBT orientation has a significant effect on the ferroelectric properties of Pt/NBT/LSCO heterostructures. The remnant polarization 2Pr values for NBT(111), NBT(110) and NBT(001) are 87.5, 62.6 and 28.5 μC/cm2, respectively, and thus 2Pr(111)>2Pr(110)>2Pr(001). NBT(111) shows the best ferroelectric properties (Pr=41.3 μC/cm2), excellent fatigue-resisting (up to 1010 cycles) and retention performance (duration 104s). The 2Pr-T association 2 Pr=41.72+16.05*T0.35 for NBT(111) was obtained according to the curve fitting, it is found that the NBT orientation has a significant effect on the PV effect for PT/NBT/LSCO photovoltaics and the open-circuit voltage ∆Voc. The short-circuit current ∆Jsc of polarization regulate intensity follows the laws of ∆Voc-111>∆Voc-110>∆Voc-001 and ∆Jsc-111>∆Jsc-110>∆Jsc-001, the Jsc for Pt/NBT(111)/LSCO heterostructures increases linearly with the illumination Ip increasing, while the Voc decreases linearly. The ferroelectro-polarized modulation PV mechanism was investigated by analyzing band structure of the Pt/NBT/LSCO heterostructures, which is attributed to the coupling effect of the ferroelectric depolarization field and the interfacial Schottky barrier.

Investigating different carbon-based target materials: Can we improve ionization in HiPIMS for the deposition of diamondlike carbon films?

Investigating different carbon-based target materials: Can we improve ionization in HiPIMS for the deposition of diamondlike carbon films?

Enhanced corrosion resistance of graphite-like carbon coatings via dense ta-C interlayer encapsulating

Taking the combination of atomic bond density, in this work, the tetrahedral amorphous carbon (ta-C) layer with high sp3 bond were especially introduced into the sp2-riched graphite-like carbon (GLC) coatings, using a hybrid filtering cathodic arc and magnetron sputtering deposition technique. The focus was elaborated on the electrochemical behavior of coatings against the stimulated chloride solutions for marine applications. Results showed that inserting dense ta-C layer significantly encapsulated the intrinsic pore defects within GLC growth, thereafter enhancing the corrosion resistance remarkably. In particular, the coating porosity was reduced from 10.84 % for pristine GLC system to 3.19 % for GLC with ta-C sealing layer, accompanying with a reduction in corrosion current to 7.8 × 10−9 A/cm2 and an increment in protective efficiency to maximum value of 95.49 %. The small angle X-ray scattering (SAXS) analysis evidenced qualitatively that the coating porosity was suppressed greatly, which were well consisted with the enhanced corrosion resistance of GLC coating with ta-C sealing layer. Furthermore, the balance between pores sealing and interfacial matching could be tailored by controlling the thickness ratio of ta-C and GLC layers, enabling the achievement of both the compact structure and the superior corrosion resistance. These observations offer a new promising strategy to develop the protective coatings for harsh marine environment that required both excellent capability against corrosion and friction with long lifetime.

Terahertz sensing with a 3D meta-absorbing chip based on two-photon polymerization printing

The narrowband meta-absorbers exhibit significantly enhanced electromagnetic confinement capabilities, showcasing broad application prospects in sensing fields. They can be applied for biomarker detection, chemical composition analysis, and monitoring of specific gas in the environment. In this work, we propose a 3D meta-absorber with an out-of-plane plasma mechanism based on a two-photon printing system. Compared to the conventional fabrication of a metal-insulator-metal 2D meta-absorber, the 3D absorber is composed of a metal layer and a resin layer from top to bottom; its manufacturing process is simpler, only including two-photon printing and magnetron sputtering deposition. A noticeable absorbing resonance appears at 0.3142 THz with perfect absorbance with a high Q-factor of 104.67. The theoretical sensitivity to the refractive index of the sensor reaches up to 172.5 GHz/RIU, with a figure of merit (FOM) of 19.56. In the experiments, it was validated as a meta-absorber with high sensitivity for doxycycline (DCH). As the DCH concentration increases from 0 to 4 mg/mL, the absorption intensity decreases around 49%, while the resonant frequency shift is around 70 GHz. It reflects the real-time residual content of DCH, and is potentially applied in trace antibiotic detection. The results showcase a perfect narrowband absorption capability with strong electromagnetic confinement in the terahertz spectrum, along with high-Q sensing characteristics of DCH. Compared to 2D metamaterials, the diversity of 3D metamaterial significantly expands, and introduces additional effects to provide greater flexibility in manipulating electromagnetic waves. The 3D device offers opportunities for the application of terahertz biochemical sensing.

Improving hydrogen isotope permeation resistance of (TiVAlCrZr)O multi-component metal oxide coating by O+ Ion implantation

Oxygen vacancy can greatly affect the performance of metal oxide to hydrogen isotope permeation resistance. In this work, we report a new strategy to improve the permeation resistance by oxygen ion implantation. A (TiVAlCrZr)O multi-component metal oxide film was prepared as a tritium permeation barrier on a 316 L substrate by RF magnetron sputtering deposition, and then implanted by oxygen ions to fill the oxygen vacancies inside. The grazing incidence X-rays (GIXRD) analysis showed that the pristine and the oxygen-implanted coatings were in an amorphous phase. The deuterium permeation resistance of the four coatings was tested by a gas-driven device. The result showed that the pristine coating had a permeation reduction factor (PRF) of 5,610 at 500 °C, while there was a 13.6 times of increase in PRF with an oxygen concentration of 11.4 at.% with the best-reported value of 76,500, and more oxygen ions implanted, the better the deuterium permeation resistance of the coating. The GIXRD showed that after the test the pristine coating remained amorphous, while some crystals were formed in the oxygen-implanted coating with an oxygen concentration of 11.4 at.%. Oxygen ion implantation enhanced the deuterium permeation resistance by filling the oxygen vacancies and forming of more stable state of amorphous multi-component metal oxide, which is expected to be a new type of deuterium permeation barrier.

Linearization and characterization of the Wemple – DiDomenico model of ZnO/Ni/ZnO tri-layer thin films prepared by ALD and DC magnetron sputtering

Our present work is devoted to analyzing the influence of Ni on the optical properties of ZnO thin films deposited on glass and Si (100) substrates, with the use of ALD for ZnO deposition and DC magnetron sputtering for Ni interlayer deposition. The compositions as well as the crystalline structure of various multilayer thicknesses of Ni (10, 30, 50, and 70 nm), that sandwiched between ZnO Films (70 nm), before being optically characterized, were carried out by the X-ray diffraction (XRD). Based on the XRD results, the crystallite size was increased with the increase of the Ni interlayer concentration. Additionally, the material densities for both ZnO and Ni show the expected close-to-bulk values in all formations, where the large cavities between atoms, on the films make the dislocation density become smaller and the surface roughness values decrease as well, with the increase of Ni interlayer concentration. Different optical properties were observed for different Ni content. The optical absorption coefficient (α), refractive index (n), and extinction coefficient (k) have been deduced from the transmission T(λ) and absorption measurements A(λ). The optical energy gap Egoptare estimated from Tauc΄s extrapolation procedure and the Kubelka-Munk approach. The static refractive index (no), the oscillator energy (Eo), and the dispersion energy (Ed) are calculated using the Wemple-DiDomenico (WDD) theoretical model. Analysis of third-order nonlinear optical properties in crystalline ZnO/Ni/ZnO are being detailed. These promising results imply that the high-quality films produced by ALD, show how the insertion of Ni could enhance the quality of the optical properties of ZnO films.

The ferroelectric and piezoelectric properties of (Hf1−x Ce x )O2 films on indium tin oxide/Pt/TiO x /SiO2/(100)Si substrates obtained using a no-heating radio-frequency magnetron sputtering deposition method

The effect of composition and film thickness on the ferroelectric and piezoelectric properties of (Hf1−x Ce x )O2 films deposited without substrate heating was investigated. (Hf1−x Ce x )O2 films with various x values (x = 0.07–0.27) and thickness (150–880 nm) were deposited via RF magnetron sputtering on indium tin oxide (ITO)/Pt/TiO x /SiO2/(100)Si substrates. The crystalline phases of the films were observed by X-ray diffraction. The measurements of electrical properties revealed ferroelectric phases in the x range of 0.11–0.21. The film with x = 0.16 exhibited the maximum remanent polarization (Pr) of 15 μC cm−2, as well as the highest effective piezoelectric coefficient. In addition, the ferroelectric and structural properties remained almost unchanged with increasing film thickness. Therefore, the no-heating deposition of ferroelectric (Hf1−x Ce x )O2 films and their phase stability with respect to thickness were demonstrated in this study. This work provides a pathway for the deposition of ferroelectric (Hf1−x Ce x )O2 films on flexible, wearable sensors.

Synergistic Enhancement of Efficient Perovskite/Quantum Dot Tandem Solar Cells Based on Transparent Electrode and Band Alignment Engineering

AbstractPerovskite‐based tandem solar cells have demonstrated high potential for overcoming the Shockley–Queisser limit. Routine bandgap (RBG, ≈1.55 eV) perovskites have achieved a perfect balance between efficiency and stability. The narrow bandgap (NBG) candidates for RBG perovskite‐based tandem devices are very limited. Lead sulfide (PbS) colloidal quantum dots (CQDs) are a promising partner due to their broad absorption spectra. However, the efficiency of RBG perovskite/QD tandem devices still lags behind. Herein, efficient RBG perovskite/QDs four‐terminal tandem photovoltaics are successfully implemented through synergistic enhancement from transparent electrode and band alignment Engineering. For tin doped indium oxide (ITO) electrodes, their conductivity and near‐infrared transparency are leveraged using magnetron sputtering and reactive plasma deposition (RPD) methods. Furthermore, instead of traditional zinc oxide, aluminum‐doped zinc oxide (AZO) is developed to enhance the carrier extraction capability of PbS QD bottom cells. Based on the above enhancements, ≈0.95 eV PbS solar cells achieve a record efficiency of 14.14%. Integrated with the front semi‐transparent perovskite solar cells, the four‐terminal perovskite/QD tandem device reaches a record efficiency of 26.12%. The synergistic combination of the RBG perovskite and NBG QD devices provides promising prospects for tandem photovoltaics.

Ion-beam induced compositional and structural changes of Al-Cu-Co multilayer stacks

The present work deals with the investigation of ion-beam assisted annealing/mixing effects on compositional and structural changes in Al-Cu-Co multilayers. 800 nm thick Al64Cu20Co16 multilayers prepared by magnetron sputtering deposition, consisting of 28 successive single-metal Al-, Cu-, and Co-nanolayers were treated by thermal annealing at 300 °C, 400 °C, or 500 °C as well as ion irradiation by 30 MeV Cu5+ ions at fluences of 1x1013 to 5x1014 with an average flux of 2.38 × 1010 at.cm−2s−1. The samples were characterized with SEM, EDX, XRD, and TEM including HAADF. In contrast to the original multilayer, the treated samples were found to consist of two types of alternating nanolayers. A wider coarse-grained structurally and chemically homogeneous single-phase nanolayer formed by Al2Cu, and a narrow fine-grained two-phase nanolayer, which has a heterogeneous composite structure in which the central Co sublayer (being a residue of the original single-metal Co nanolayer) is surrounded from both sides with Al-Co sublayers, consisting of Al9Co2. This Co sublayer is considered to be a diffusion blocker for Al and Cu as well as hindering the movement of borders between particular nanolayers. The formation of a ternary phase in the investigated samples was not confirmed in any of the samples.