Seed Layer Research Articles

Sputtered Zero‐Excess Electrodes with Metallic Seed Layers for Solid‐State Sodium Batteries

Zero‐excess sodium metal solid‐state batteries offer improved safety, lower cost, higher energy density, and reduced resource dependency compared to today’s lithium‐ion technology. This study demonstrates the fabrication of zero‐excess electrodes with unprecedented stability during plating/stripping cycles. The fabrication process involves the sputter deposition of 20 nm metallic seed layers – zinc, silver, indium, or tin – onto NASICON (Na3.4Zr2Si2.4P0.6O12) ceramic separators, followed by the sputter deposition of a 30 µm copper current collector. The favorable influence of these seed layers on the in‐situ formation of the sodium|NASICON interface is examined through nucleation and cycling experiments, with a sodium metal reservoir serving as the non‐limiting counter electrode. Due to alloy formation the seed layers – particularly tin – stabilize sodium nucleation and cycling substantially and reduce dendrite formation compared to reference cells with bare copper current collectors. Sodium loss during cycling is primarily attributed to local cracking of the current collector and its partial delamination from the NASICON. Compared to polished NASICON, a roughened surface reduces the resistance e.g. of the counter electrode 200‐fold to approx. 1 Ωcm² at 3 MPa and suppresses delamination further.

Tunable Growth of Layered Double Hydroxide Nanosheets through Hydrothermal Conversion of Atomic Layer Deposition Seed Layers

Tunable Growth of Layered Double Hydroxide Nanosheets through Hydrothermal Conversion of Atomic Layer Deposition Seed Layers

Conformal zinc sulfide coating of vertically aligned ZnO nanorods by two-step hydrothermal synthesis on wide bandgap seed layers for lead-free perovskite solar cells

Vertically aligned ZnO nanorods (NRs) were grown hydrothermally on the wide bandgap (∼3.86 – 4.04 eV) seed layers (SLs) of grain size ∼162 ± 35 nm, prepared using ball-milled derived ZnO powder. The synthesized ZnO NRs were further decorated with ZnS nanocrystals to achieve a ZnO NR-ZnS core–shell (CS)-like nano-scaffolds by a subsequent hydrothermal synthesis at 70 °C for 1 h. UV-Vis-NIR spectroscopy, x-ray diffractometry (XRD), Raman spectroscopy and Field emission scanning electron microscopy (FESEM) coupled with Energy dispersive x-ray spectroscopy (EDX) analyses confirmed the formation of ZnS atop the vertically aligned ZnO NR arrays of ∼1.79 ± 0.17 µm length and ∼165 ± 27 nm diameter. Transmission electron microscopy (TEM)/EDX analyses revealed that vertically aligned ZnO NRs (core dia. ∼181 ± 12 nm) arrays are conformally coated by an ultrathin ZnS (∼25 ± 7 nm) shell layer with a preferential ZnS{111}/ZnO{10-10}-like partial epitaxy. The ZnO NRs exhibited a sharp band edge near ∼384 nm having optical bandgap energy (E g) of ∼3.23 eV. However, the ZnO NR-ZnS CS exhibited double absorption bands at E g ∼ 3.20 eV (ZnO-core) and E g ∼ 3.78 eV (ZnS-shell). The ZnS{111}/ZnO{10-10}-nano-scaffolds could be utilized to facilitate the enhanced absorption of UV photons as well as the radial junction formation between the Pb-free perovskite absorber and ZnS/ZnO NRs layers.

Continuous Electroless Seed Layer Deposition in Through-Glass-Vias by Ultrasonic Agitation

Continuous Electroless Seed Layer Deposition in Through-Glass-Vias by Ultrasonic Agitation

Effects of Bath Composition, Current Density and Annealing Conditions on the Properties of the Electrodeposited Ni Seed Layer for Cu Contacts in Si Solar Cells

Effects of Bath Composition, Current Density and Annealing Conditions on the Properties of the Electrodeposited Ni Seed Layer for Cu Contacts in Si Solar Cells

Low Transmission Loss Cu Wirings with Smooth Seed Layer and High Adhesion against Prepregs

Low Transmission Loss Cu Wirings with Smooth Seed Layer and High Adhesion against Prepregs

Enhancing Adhesion and Reducing Ohmic Contact through Nickel-Silicon Alloy Seed Layer in Electroplating Ni/Cu/Ag.

Due to the lower cost compared to screen-printed silver contacts, the Ni/Cu/Ag contacts formed by plating have been continuously studied as a potential metallization technology for solar cells. To address the adhesion issue of backside grid lines in electroplated n-Tunnel Oxide Passivating Contacts (n-TOPCon) solar cells and reduce ohmic contact, we propose a novel approach of adding a Ni/Si alloy seed layer between the Ni and Si layers. The metal nickel layer is deposited on the backside of the solar cells using electron beam evaporation, and excess nickel is removed by H2SO4:H2O2 etchant under annealing conditions of 300-425 °C to form a seed layer. The adhesion strength increased by more than 0.5 N mm-1 and the contact resistance dropped by 0.5 mΩ cm2 in comparison to the traditional direct plating Ni/Cu/Ag method. This is because the resulting Ni/Si alloy has outstanding electrical conductivity, and the produced Ni/Si alloy has higher adhesion over direct contact between the nickel-silicon interface, as well as enhanced surface roughness. The results showed that at an annealing temperature of 375 °C, the main compound formed was NiSi, with a contact resistance of 1 mΩ cm-2 and a maximum gate line adhesion of 2.7 N mm-1. This method proposes a new technical solution for cost reduction and efficiency improvement of n-TOPCon solar cells.

Study of Seed Layer Growth for Superconducting Fe(Se,Te) Film Deposition

Study of Seed Layer Growth for Superconducting Fe(Se,Te) Film Deposition

Effect of ZnO Interfacial Seed Layer in Sol–Gel Grown ZnMgO Ferroelectric

Effect of ZnO Interfacial Seed Layer in Sol–Gel Grown ZnMgO Ferroelectric

Structural Color Formation of ZnO Nanorods Using Gold as a Seed and Reflective Layer

Structural Color Formation of ZnO Nanorods Using Gold as a Seed and Reflective Layer

P‐7.8: Resistance Reduction in Molybdenum gate electrode by W Seed Layer

P‐7.8: Resistance Reduction in Molybdenum gate electrode by W Seed Layer

Regulating Charge Transport Dynamics at the Buried Interface and Bulk of Perovskites by Tailored‐phase Two‐dimensional Crystal Seed Layer

AbstractTargeting the trap‐assisted non‐radiative recombination losses and photochemical degradation occurring at the interface and bulk of perovskite, especially the overlooked buried bottom interface, a strategy of tailored‐phase two‐dimensional (TP‐2D) crystal seed layer has been developed to improve the charge transport dynamics at the buried interface and bulk of perovskite films. Using this approach, TP‐2D layer constructed by TP‐2D crystal seeds at the buried interface can induce the formation of homogeneous interface electric field, which effectively suppress the accumulation of charge carriers at the buried interface. Additionally, the presence of TP‐2D crystal seed has a positive effect on the crystallization process of the upper perovskite film, leading to optimized crystal quality and thus promoted charge transport inside bulk perovskites. Ultimately, the best performing PSCs based on TP‐2D layer deliver a power conversion efficiency of 24.58 %. The devices exhibit an improved photostability with 88.4 % of their initial PCEs being retained after aging under continuous 0.8‐sun illumination for 2000 h in air. Our findings reveal how to regulate the charge transport dynamics of perovskite bulk and interface by introducing homogeneous components.

Regulating Charge Transport Dynamics at the Buried Interface and Bulk of Perovskites by Tailored-phase Two-dimensional Crystal Seed Layer.

Targeting the trap-assisted non-radiative recombination losses and photochemical degradation occurring at the interface and bulk of perovskite, especially the overlooked buried bottom interface, a strategy of tailored-phase two-dimensional (TP-2D) crystal seed layer has been developed to improve the charge transport dynamics at the buried interface and bulk of perovskite films. Using this approach, TP-2D layer constructed by TP-2D crystal seeds at the buried interface can induce the formation of homogeneous interface electric field, which effectively suppress the accumulation of charge carriers at the buried interface. Additionally, the presence of TP-2D crystal seed has a positive effect on the crystallization process of the upper perovskite film, leading to optimized crystal quality and thus promoted charge transport inside bulk perovskites. Ultimately, the best performing PSCs based on TP-2D layer deliver a power conversion efficiency of 24.58 %. The devices exhibit an improved photostability with 88.4 % of their initial PCEs being retained after aging under continuous 0.8-sun illumination for 2000 h in air. Our findings reveal how to regulate the charge transport dynamics of perovskite bulk and interface by introducing homogeneous components.

Enhancement of Coercivity for Sm(Fe-Co)<sub>12</sub>-B Thin Films by Introduction of Sm Seed Layer

Enhancement of Coercivity for Sm(Fe-Co)<sub>12</sub>-B Thin Films by Introduction of Sm Seed Layer

Effect of the Seed Layer on the Growth and Charge Transfer Behavior of Zn2SnO4 Nanorods in Photoelectrochemical Water Splitting.

The growth of Zn2SnO4 nanorods on two differently prepared ZnO seed layers is demonstrated using a hydrothermal approach. The ZnO seed layers are prepared using dip-coating and electrodeposition techniques. The grown Zn2SnO4 nanorods are in the cubic phase. However, the different seed layers result in alternation in the diameter of grown Zn2SnO4 nanorods. The photocurrent of Zn2SnO4 nanorods grown on an electrodeposited ZnO seed layer is ∼4.5 times larger than that of Zn2SnO4 grown on a dip-coated ZnO seed layer. The Nyquist plots of Zn2SnO4 nanorods on the electrodeposited ZnO seed layer result in a lower charge transfer resistance (Rct = 37.7 Ω) and a lower bulk resistance (Rbulk = 64 kΩ), improving the charge transport properties. The change in diameter of Zn2SnO4 nanorods significantly alters the charge transfer behavior. The calculated charge injection efficiency did not exhibit a significant change. However, there was a 1.6-fold enhancement observed in the charge separation efficiency for Zn2SnO4 when grown on an electrodeposited seed layer.

Improved Adhesion of Direct Copper Seed Layer by Medium-Vacuum Sputtering Using Vacuum Ultraviolet Light

A sputtering method is used to form the seed layer for copper electric plating. In general, copper sputtering has weak adhesion to resin, so titanium sputter is combined to increase the adhesion strength. However, etching in the lithography process requires two types of processes, titanium and copper metal. Adhesion strength was improved by performing vacuum ultraviolet (VUV) treatment as a pretreatment for medium-vacuum sputtering. We discovered the relationship between the hydroxyl groups on the resin surface and the adhesion strength by the chemical modification XPS method. Furthermore, by XPS analysis of the peeled copper interface, the adhesion mechanism between the resin and copper due to VUV irradiation was estimated. We evaluated the absorption properties in the vacuum ultraviolet region of a thinly polished glass epoxy resin. We investigated the behavior of functional groups at the interface and considered the effect of vacuum ultraviolet light in the depth direction.

Enhancing Electrical and Physical Contacts of Copper‐Electroplated Silicon Heterojunction Solar Cells through Chemical Pretreated Seed Layers

Copper electroplating offering the potential to replace low‐temperature sintered silver pastes holds significant promise as a metallization process for silicon heterojunction (SHJ) solar cells (SCs). To unlock the full potential of copper electroplating, it is crucial to enhance the contact properties between the electroplated grids and the indium tin oxide (ITO) films, addressing both contact resistivity and physical adhesion. Herein, a zinc‐assisted Fe2+ system to modify the ITO film is used, leading to the formation of an In/Sn/SnO mixed‐metal transition layer. This transition layer serves as a seed layer for metal electroplating, reducing contact resistivity and enhancing the mechanical connection between the electroplated metals and the ITO films. Following the ITO pretreatment process, the contact resistivity is significantly reduced from 1.4 to 0.2 mΩ cm2, and the peel force value of the pretreated sample reaches 14.2 N mm−1, which is 75.3% higher than that of the untreated sample. The proof‐of‐concept SHJ SC with copper electroplating after ITO pretreatment achieves a remarkable power conversion efficiency of 22.6%. These results clearly demonstrate that ITO pretreatment using the zinc‐assisted Fe2+ system is an effective approach for enhancing contact properties and improving the performance of copper‐electroplated SHJ SCs, showcasing significant potential for industry applications.

Strontium Vanadate Deposited by ALD: Toward a New Synthesis Approach

Transparent conductive oxides (TCOs) have a wide range of potential applications in fields such as photovoltaics, touch screens, and smart windows. The challenging task when developing conventional TCOs like tin-doped indium oxide (ITO) by the traditional method is to make them more conducting by increasing the concentration of charge carriers without compromising the optical transparency [1]. Another novel approach involves increasing the plasma energy to widen the transparency window by increasing the charge carriers' effective mass. This approach has led to growing interest in perovskite transition metal oxides such as CaVO3 and SrVO3 due to their strong electronic correlation, which results in plasma energy shifting to higher energies than classical TCOs [2,3]. However, obtaining a crystallized film in the perovskite SrVO3 phase for optimal electrical conduction and optical transparency is challenging, particularly at low growth temperatures and when deposited on amorphous substrates like glasses [2, 4].As a result, atomic layer deposition (ALD) has emerged as a promising technique for depositing conformal layers on large surfaces with high aspect ratios and low thermal budgets. In this study, we investigated the deposition of strontium vanadium oxide films by ALD using vanadium tri-isopropoxide (VTIP) as the vanadium precursor, strontium bis(isopropylcyclopentadienyl) (Sr(iPr3Cp)2) from Air Liquide company as the strontium precursor, and water as a reagent, respectively. We deposited SrVO3 films on (100) Silicon and glass substrates at 240°C and annealed them under forming gas (95% Ar, 5% H2) at 500°C for one hour. We paid particular attention to the deposition of an anatase TiO2 buffer layer to promote the crystallization of SVO.The unannealed films were found to be completely amorphous whatever the substrate, and regardless of the presence or not of the TiO2 crystallized buffer. The EDX, STEM-HAADF and SIMS analyses revealed that the buffer is a key element to avoid the Si diffusion in SVO layer, before, and even more upon annealing. The annealed samples with a buffer layer deposited on both substrates were crystallized into various SrxVyOz phases according to the Sr amount, controlled by the Sr cycles ratio (RSR) (figure). The XRD data allowed the identification of the Sr3VO8 and Sr2VO4 phases, where the last one favors the higher Sr amount. The influence of the substrate is significant and discussed. Furthermore, we characterized the films' optical properties using spectroscopic ellipsometry in the UV-visible range. We analyzed the refractive index and extinction coefficient behavior according to the Sr amount and evaluated the effect of annealing. We estimated the band gap energy using Tauc-Lorentz and Tauc plot models and discussed it in relation to the Sr amount and the obtained phases.Our study provides not only valuable insights into the deposition and characterization of SrVO3 thin films for potential TCO applications, but also on Sr3VO8 and Sr2VO4 phases, which may be of interest for their transparent oxide optical properties. New ALD growth strategies to improve the SrVO3 phases will be presented as a perspective of this study and as an example of using different V precursor or reactive atmospheres during ALD process.[1] S.C. Dixon, D.O. Scanlon, C.J. Carmalt, I.P. Parkin, "n-Type doped transparent conducting binary oxides: an overview", Journal of Materials Chemistry C, 4, 29 (2016), pp. 6946-6961[2] Zhang, Lei, et al. "Correlated metals as transparent conductors." Nature materials 15.2 (2016): 204-210.[3] Boileau, Alexis, et al. "Highly Transparent and Conductive Indium‐Free Vanadates Crystallized at Reduced Temperature on Glass Using a 2D Transparent Nanosheet Seed Layer." Advanced Functional Materials 32.5 (2022): 2108047.[4] A. Boileau, A. Cheikh, A. Fouchet, A. David, C. Labbé, P. Marie, F. Gourbilleau, U. Lüders, "Tuning of the optical properties of the transparent conducting oxide SrVO3 by electronic correlations", Advanced Optical Materials, 7, 7 (2019), pp. 1801516 Figure 1

In Situ Formation of 2D Perovskite Seeding for Record-Efficiency Indoor Perovskite Photovoltaic Devices.

With 40% efficiency under room light intensity, perovskite solar cells (PSCs) will be promising power supplies for low-light applications, particularly for Internet of Things (IoT) devices and indoor electronics, shall they become commercialized. Herein, β-alaninamide hydrochloride (AHC) is utilized to spontaneously form a layer of 2D perovskite nucleation seeds for improved film uniformity, crystallization quality, and solar cell performance. It is found that the AHC addition indeed improves film quality as demonstrated by better uniformity, lower trap density, smaller lattice stress, and, as a result, a 10-fold increase in charge carrier lifetime. Consequently, not only does the small-area (0.09 cm2 ) PSCs achieve a power conversion efficiency of 42.12%, the large-area cells (1.00 cm2 , and 2.56 cm2 ) attain efficiency as high as 40.93%, and 40.07% respectively. All of these are the highest efficiency values for indoor photovoltaic cells with similar sizes, and more importantly, they represent the smallest efficiency loss due to area scale-up. This work provides a new method to fabricate high-performance indoor PSCs (i-PSCs) for IoT devices with great potential in large-area printing technology.

Interfacial reinforcement strategy of basalt fiber/polymer composite constructed by interlocking interface composed of ZnO nanowires

Basalt fiber (BF) as a promising reinforcing material, is used widely to prepare polymer composite, but poor interfacial interaction with polymer matrix deteriorates the reinforcement effect. Here, a biomimetic “root-like” BF with laterally-grown zinc oxide (ZnO) nanowires was prepared via dopamine surface modification and two-step hydrothermal method. By virtue of the coordination of catechol groups with Zn2+ ions, the polydopamine coating layer provided the strong affinity with the ZnO seeds layer and facilitated the direction growth of ZnO nanowires, with firm immobilization on the BF surface. Accordingly, the robust interlocking interface was successfully constructed in the root-like BF/polymer composite by penetrating laterally-grown ZnO nanowires into polymer matrix, greatly reinforcing the interfacial adhesion. Compared to conventional surface chemical treatment only suitable for a single specific system, the interfacial interlocking effect mainly depended on the formation of the laterally-grown ZnO nanowires, rather than intrinsic properties of polymer components, so as to be applied to a wide range of polymer composites. This can be exemplified by 265% and 197% increases in interfacial strength of the root-like BF-filled polypropylene (PP) and polydimethylsiloxane (PDMS) composite over that of the corresponding pristine BF ones.