Nanowire Contacts Research Articles

Constructing Long and Stable Ag‐Al2O3 Core–Shell Nanowires for Humidity Sensing and Triboelectric Energy Generation

Silver nanowires (AgNWs) are a promising alternative material to indium tin oxide as flexible transparent electrodes owing to their excellent optoelectrical properties and mechanical performance. However, the main challenge is the poor stability under diverse environments, ranging from high humidity, chemical exposure, and dynamic mechanical deformation. Herein, ultralong AgNWs (≈100 μm) have been synthesized via controlling growth kinetics by a facile acetic acid‐assisted solvothermal method, further decorated with a thin Al2O3 layer by electrodeposition to form a core–shell architecture. The resultant films based on Ag‐Al2O3 core–shell nanowires (NWs) possess a higher conductivity while preserving the optical transparency due to the enhanced NWs contact. More importantly, the constructed films exhibit strong resistance to various conditions, such as exposure to high temperature/humidity and immersion in NaCl, HCl, and Na2S solutions. The laser‐etched interdigital electrodes based on the chemically stable AgNWs are further integrated with graphene oxide layer for humidity sensing and respiration monitoring. Furthermore, the developed NWs with superior mechanical stability are constructed as triboelectric nanogenerators for electricity generation, and reliable output performance has been demonstrated. This work provides a convenient, scalable, and cost‐effective solution that offers great potential for designing robust, transparent electrodes for next‐generation flexible electronics.

Microscopic insights into metal diffusion and ohmic contact formation in delta-doped GaAs/(Al,Ga)As core/shell nanowires

Semiconductor nanowires (NWs) are promising candidates for use in electronic and optoelectronic applications, offering numerous advantages over their thin film counterparts. Their performance relies heavily on the quality of the contacts to the NW, which should exhibit ohmic behavior with low resistance and should be formed in a reproducible manner. In the case of heterostructure NWs for high-mobility applications that host a two-dimensional electron gas, ohmic contacts are particularly challenging to implement since the NW core constituting the conduction channel is away from the NW surface. We investigated contact formation to modulation-doped GaAs/(Al,Ga)As core/shell NWs using scanning transmission electron microscopy, energy dispersive x-ray spectroscopy and electron tomography to correlate microstructure, diffusion profile and chemical composition of the NW contact region with the current–voltage (I–V) characteristics of the contacted NWs. Our results illustrate how diffusion, alloying and phase formation processes essential to the effective formation of ohmic contacts are more intricate than in planar layers, leading to reproducibility challenges even when the processing conditions are the same. We demonstrate that the NW geometry plays a crucial role in the creation of good contacts. Both ohmic and rectifying contacts were obtained under nominally identical processing conditions. Furthermore, the presence of Ge in the NW core, in the absence of Au and Ni, was found as the key factor leading to ohmic contacts. The analysis contributes to the current understanding of ohmic contact formation to heterostructure core/shell NWs offering pathways to enhance the reproducibility and further optimization of such NW contacts.

SkyBridge 2.0: A Fine-grained Vertical 3D-IC Technology for Future ICs

Gate-all-around field effect transistors (FETs) are set to replace FinFETs to enable continued miniaturization of ICs in the deep nanometer regime. IMEC and IRDS roadmaps project that 3D integration of gate-all-around FETs is a key path for the IC industry beyond 2024. In this article, we present SkyBridge 2.0, an IC technology featuring high density fine-grained 3D integration of vertical gate-all-around nanowire FETs, contacts, and interconnect while also solving 3D routability. We utilize industry-standard EDA tools to develop a customized design and technology co-optimization (DTCO) flow to design and evaluate SkyBridge 2.0. This DTCO flow covers process emulation of standard cells and SRAM to enable scalable manufacturing pathway, TCAD characterization of vertical nanowire FETs to obtain IV and CV characteristics, compact modeling accurately the device behavior, RC parasitic extraction of 3D interconnects and performance, and power and area assessment using ring oscillators. The technology assessment using ring oscillators shows that SkyBridge 2.0 at the chosen design point, using 10 nm nanowires, achieves ∼18% performance and 31% energy efficiency benefits compared to 7 nm FinFET technology. Area analysis of logic cells shows up to six times density benefits versus aggressively scaled 2D-CMOS cells. In addition to logic, we architect 3D SRAM to support low-power memory designs. SkyBridge 2.0 SRAM shows ∼20% improvement in read and write static noise margin, up to three times lower leakage current, and up to four times density benefits compared to 7 nm FinFET technology.

Enhancing the memristive effects in SnO2 nanowire networks

We present a study of SnO2 nanowire network acting as a resistive memory device. Charge transport features in these devices were controlled by modulating the behavior of the energy barriers of nanowire-nanowire interfaces and the Schottky barrier under the electrodes. Both barriers were found to be affected by the distribution and availability of charges along the nanowires mesh and in the surrounding atmosphere. The consequent memristive effect was dependent of the environment conditions but also controllable by managing the availability of charges for the transport properties. Using a polymeric barrier layer to avoid the direct contact of nanowires with the surrounding atmosphere proved to be an effective method to obtain reliable/better results after many memristive cycles. This simple procedure of polymeric coating offers some benefits such a more stable gain and a ON/OFF ratio improvement (from 1.55 to 3.60). Furthermore, coated devices showed potential features for use in synaptic learning applications.

Locally Thinned, Core-Shell Nanowire-Integrated Multi-gate MoS2 Transistors for Active Control of Extendable Logic.

Field-effect transistor (FET) devices with multi-gate coupled structures usually exhibit special electrical properties and are suitable for fabricating multifunctional devices. Among them, the 1D nanowire gate configuration has become a promising gate design to tailor 2D FET performances. However, due to possible short circuiting induced by nanowire contact and the high requirement for precision manipulation, the integration of multi-nanowires as gates in a single 2D electronic system remains a grand challenge. Herein, local laser--thinned multiple core-shell SiC@SiO2 nanowires are successfully integrated into MoS2 transistors as multi-gates for active control of extendable logic applications. Nanowire gates (NGs) locally enhance the carrier transportation, and the use of multiple NGs can achieve designed band structures to tune the performance of the device. For core-shell structures, a semiconducting core is used to introduce a gate bias, and the insulating shell provides protection against short circuiting between NGs, facilitating nanowire assembly. Furthermore, a global control gate is introduced to co-tune the overall electrical characteristics, while active control of logic devices and extendable inputs are achieved based on this model. This work proposes a novel nanowire multi-gate configuration, which provides possibilities for localized, precise control of band structures and the fabrication of highly integrated, multifunctional, and controllable nano-devices.

Biocompatibility and Connectivity of Semiconductor Nanostructures for Cardiac Tissue Engineering Applications.

Nano- or microdevices, enabling simultaneous, long-term, multisite, cellular recording and stimulation from many excitable cells, are expected to make a strategic turn in basic and applied cardiology (particularly tissue engineering) and neuroscience. We propose an innovative approach aiming to elicit bioelectrical information from the cell membrane using an integrated circuit (IC) bearing a coating of nanowires on the chip surface. Nanowires grow directly on the backend of the ICs, thus allowing on-site amplification of bioelectric signals with uniform and controlled morphology and growth of the NWs on templates. To implement this technology, we evaluated the biocompatibility of silicon and zinc oxide nanowires (NWs), used as a seeding substrate for cells in culture, on two different primary cell lines. Human cardiac stromal cells were used to evaluate the effects of ZnO NWs of different lengths on cell behavior, morphology and growth, while BV-2 microglial-like cells and GH4-C1 neuroendocrine-like cell lines were used to evaluate cell membrane-NW interaction and contact when cultured on Si NWs. As the optimization of the contact between integrated microelectronics circuits and cellular membranes represents a long-standing issue, our technological approach may lay the basis for a new era of devices exploiting the microelectronics' sensitivity and "smartness" to both improve investigation of biological systems and to develop suitable NW-based systems available for tissue engineering and regenerative medicine.

The Shearing Behavior of Nanowire Contact Pairs in Air and the Role of Humidity

A new technique based on optical microscope nanomanipulation is developed to permit optical observation of the shearing process between cantilevered nanowires (NWs). Real‐time observation of the deflection shape of NWs during shearing under controlled environmental conditions enables their shear stress evolution to be evaluated with respect to relative humidity (RH). The average static and kinetic shear strengths, and MPa, are found to be insensitive to the RH within the range of 40–60%. When the RH increased to 74%, the shear strength values increase to and MPa. When the RH decreases to 20%, a dramatic increase in the static and kinetic shear strengths is observed: and MPa. Water films absorbed on the surface of NWs within the RH range of 40–60% can lubricate their frictional interface and thus dramatically decrease the shear strength. At high RH of above , the viscous effects of a water meniscus condensed around the contact point between two NWs can significantly enhance the shear strength and dampen stick‐slip behavior. The detachment of two NWs is then controlled by the rupture of a meniscus bridge, leading to high ultimate shear strength value of several tens of MPa.

Stretchable Printed Circuit Board Based on Leak-Free Liquid Metal Interconnection and Local Strain Control.

In order to realize a transition from conventional to stretchable electronics, it is necessary to make a universal stretchable circuit board in which passive/active components can be robustly integrated. We developed a stretchable printed circuit board (s-PCB) platform that enables easy and reliable integration of various electronic components by utilizing a modulus-gradient polymeric substrate, liquid metal amalgam (LMA) circuit traces, and Ag nanowire (AgNW) contact pads. Due to the LMA-AgNW biphasic structure of interconnection, the LMA is hermetically sealed by a homogeneous interface, realizing complete leak-free characteristics. Furthermore, integration reliability is successfully achieved by local strain control of the stretchable substrate with a selective glass fiber reinforcement (GFR). A strain localization derived by GFR makes almost 50,000% of strain difference within the board, and the amount of deformation applied to the constituent elements can be engineered. We finally demonstrated that the proposed integrated platform can be utilized as a universal s-PCB capable of integrating rigid/conventional electronic components and soft material-based functional elements with negligible signal distortion under various mechanical deformations.

Directly grown Te nanowire electrodes and soft plasma etching for high-performance MoTe2 field-effect transistors

Contact tailoring for two-dimensional (2D) transition metal dichalcogenides (TMDs) to achieve high-performance devices remains a challenge. Fermi-level pinning at 2D TMD–metal contacts leads to a Schottky barrier for contacts. In addition, when there are no dangling bonds between 2D TMDs and contacts, the contact resistance increases. In this study, Te nanowire (NW) contacts were employed for a MoTe2 p-channel of enhancement mode field-effect transistor (FET). The Te NWs were directly grown on 2D MoTe2 film by metal–organic chemical vapor deposition and selectively etched by a soft plasma etching technique for contact isolation. Using t-Te NW contacts on three-atomic-layer MoTe2, a highly effective field-effect mobility of 543.9 cm2/Vs, as well as ohmic contacts and atomic hybridization, was achieved. These results of t-Te NW electrodes provide a novel device structure for p-type 2D TMD transistors with excellent performances. Further, they offer a practical guideline for wafer-scale 2D TMD-based high-performance electronics and optoelectronics.

About a fundamental uncertainty of the contact angle of the catalyst drop on the top of the nanowire

In this paper, we aim to explain a fundamental uncertainty of the contact angle of the drops catalyzing vapor–liquid–solid growth of semiconductor nanowires (NWs). We developed the concepts about the crystallization processes occurring near the triple-phase boundary as well as the conditions of equilibrium wetting of NW top surface singular with a catalyst liquid drop characterized by the NW contact angle. We demonstrated that due to either dissolution of the crystallizable substance or its precipitation from the liquid catalyst drop on the NW tip, the wetting perimeter of the drop is not fixed and the drop can take an equilibrium shape with the NW contact angle, which does not satisfy Young's equation. The NW contact angle corresponds to the indifferent equilibrium of the catalyst droplet because of the wetting hysteresis. We proposed that the fundamental uncertainty of the NW contact angle of the catalyst drop saturated with a crystallizable substance at the NW tip is a result of the interaction of two opposing competing processes: the spheroidization of the catalytic liquid during the gravity neutralization and the wetting. We concluded that the steady-state NW contact angle of the drop depends on the free surface energies of the solid/liquid and liquid/vapor phase boundaries but does not depend on the free surface energy of the vertical sidewalls of the NWs. In this paper, we also proposed a new method to find the free surface energies of phase boundaries by the shape of the catalyst droplet on the NW tip as well as on the substrate. The paper also presents the results of obtaining the interphase free energy of the boundaries in Si-Au, Si-Cu, Ge-Au, GaAs-Au, InAs-Au, SiC-Fe, InP-Au, and so on systems.

Exploring nanowire regrowth for the integration of bottom-up grown silicon nanowires into AFM scanning probes

Bottom-up grown single-crystalline silicon nanowires (SiNWs) are highly intriguing to build nanoscale probes, for instance for atomic force microscopy (AFM), due to their mechanical robustness and high aspect ratio geometry. Several strategies to build such nanowire-equipped probes were explored but their fabrication is still elaborate, time-consuming and relies partly on single-crystalline substrates. Here, we explore a new strategy to fabricate AFM probes that are equipped with single-SiNW scanning tips. The conceptual evaluation begins with a discussion on the overall design and softness of such probes based on finite-element-method simulations. For the experimental realization, SiNWs were grown by the well-established gold-catalyzed vapor–liquid–solid method employing gaseous monosilane. As-grown SiNWs were subsequently transferred onto flexible membranes and even freestanding AFM microcantilever beams via mechanical nanowire contact printing. Elongation of the deposited nanowires by so-called regrowth was triggered by reusing the original gold catalyst to yield the prospective AFM scanning tip. SiNW-equipped scanning probes were created in this manner and were successfully employed for topography imaging. Although a multitude of challenges remains, the created probes showed an overall convincing performance and a superior durability.

(Invited) Vertical Gate All Around GeSn/Ge Heterostructure Transistors

In this paper we present our recent research on vertical GeSn/Ge heterojunction gate all around (GAA) nanowire pMOSFETs. The vertical nanowires were fabricated with a diameter as small as 20 nm. Our experimental results demonstrate that scaling of the nanowire diameter improves the device performance in terms of subthreshold swing, drain induced barrier lowering (DIBL) and Ion/Ioff ratio due to the better gate controllability. However, one of the big challenges for vertical nanowire transistors is the nanowire top contact resistance. Due to the very small contact area the nanowire contact resistance dominates the series source/drain resistance. The contact resistance can be lowered by optimized NiGeSn and NiGe contacts. Compared to vertical Ge homojunction nanowire GAA FETs, the utilization of GeSn as source can significantly lower the source/drain resistance. The band engineering of GeSn/Ge heterojunction for device improvement will be discussed in the paper.

Going up

Nordic researchers unveil their novel InAs/InGaAs nanowire MOSFETs on Si, which exhibit high-frequency gains for use in a gate-last configuration. The architecture of the device enables highly asymmetric capacitances, increasing its power gain. The authors' device shows a transit frequency (fT) of 120 GHz and maximum frequency (fmax) of 130 GHz, from a channel length (Lg) of 120 nm, demonstrating the state-of-the-art performance of their architecture. Moore's law states that the number of transistors on a microchip doubles roughly every 2 years, and has been the driving force behind the development of electrical devices for the past few decades. Silicon-based metal-oxide semiconductor field effect transitors (MOSFETs) in particular have become a rapidly developing area of research due to their high degree of scalability in digital applications. MOSFETs combining group 3 and group 5 elements (so called ‘III-V’ MOSFETs) in particular have performed beyond other transistor architectures in the realms of transconductance and the on-current. Difference between gate-last and gate-first fabrications SEM picture after gate-finger fabrication For higher frequency transistors, the inability to scale high-electron-mobility transistors (HEMTs) due to an insufficient gate-barrier has caused development of fT to stagnate around 700 GHz. The authors propose that better scaling in III-V MOSFETs could hold the key to surpassing HEMTs in high-frequency applications. Indeed, it has been shown that a number of planar MOSFETs recently have displayed fT values in the region of 400 GHz. The authors in their publication in Electronics Letters present the prospect of verical III-V nanowires for use in high-frequency devices. The nanowires are grown using a technique known as VLS, or ‘vapor-liquid-solid’ growth. This scheme is more easily integrated on a Silicon substrate, and also allows engineering of the band-gap properties of the semiconductor, giving rise to improved intrinsic voltage gain and a higher breakdown voltage without the deterioration of other performance metrics. The growth of vertical nanowire MOSFETs can be generally divided into two processes: gate-last and gate-first processes. Gate-first processes are generally less desirable, as they produce thin nanowire contacts and leave ungated regions at the top of the nanowire, which increases the access resistance at this point. Gate-last devices form a recessed gate and add metal to the sidewalls of the nanowire, reducing the access resistance. The gate-last MOSFETs produced by the authors here are based on InAs/In0.4Ga0.6As heterostructure nanowires which have been fabricated on a Si{111} substrate. The wire can be considered in 3 parts: a bottom segment made of highly-doped InAs, a middle segment which is unintentionally doped as the wire transitions from InAs to InGaAs and a top segment which is highly doped InGaAs. The middle and bottom segments are each 100 nm in length, whilst the top segment measures 300 nm in length. The gate connects the bottom and middle segments. The authors provide a comparison with a number of other MOSFET devices produced on Silicon. Their device shows comparable performance with the referenced works, even before the full optimisation of their device. Such optimisations will take the form of further scaling of the structure to reduce capacitances. Authors note that their device should be scalable all the way down to 25 nm. The work presented in Electronics Letters could prove to be a key piece of the puzzle when dealing with the continued minimisation of electronic circuits, with early results showing that the proposed architecture is capable of keeping up with current state-of-the-art devices.

Coulomb blockade in monolithic and monocrystalline Al-Ge-Al nanowire heterostructures

We report the realization of Ge single-hole transistors based on Al-Ge-Al nanowire (NW) heterostructures. The formation of these axial structures is enabled by a thermally induced exchange reaction at 350 °C between the initial Ge NW and Al contact pads, leading to a monolithic and monocrystalline Al-Ge-Al NW. The 25 nm-diameter Ge segment is a quasi-1D hole channel. Its length is defined by two abrupt Al-Ge Schottky tunnel barriers. At low temperatures, the device shows a single hole transistor signature with well pronounced Coulomb oscillations. The barrier strength between the Ge segment and the Al leads can be tuned as a function of the gate voltage VG. It leads to a zero conductance at VG= 0 V to a few quantum conductance at VG= –15 V. When the gate voltage increases from –5 V to –3 V, the charging energy is extracted and it varies from 0.39 meV to 2.42 meV.

Axial EBIC oscillations at core/shell GaAs/Fe nanowire contacts

Electron beam induced current (EBIC) measurements were carried out in situ in the scanning electron microscope on free-standing GaAs/Fe core–shell nanowires (NWs), isolated from the GaAs substrate via a layer of aluminum oxide. The excess current as a function of the electron beam energy, position on the NW, and scan direction were collected, together with energy dispersive x-ray spectroscopy. A model that included the effects of beam energy and Fe thickness predicted an average collection efficiency of 60%. Small spatial oscillations in the EBIC current were observed, that correlated with the average Fe grain size (30 nm). These oscillations likely originated from lateral variations in the interfacial oxide thickness, affecting the resistance, barrier potentials, and density of minority carrier recombination traps.

Sn-doped hematite modified by CaMn2O4 nanowire with high donor density and enhanced conductivity for photocatalytic water oxidation

Herein, we report a novel nanocomposite consisting of n-type Sn-doped hematite and p-type CaMn2O4 nanowire (CaMn2O4/α-Fe2O3). The nanocomposite was characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), ultraviolet-visible absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), which showed that nanospindle-like Sn-doped hematite and CaMn2O4 nanowire contact intimately in the nanocomposite, resulting in efficient charge transfer and separation. Photoelectrochemical results reveal that the nanocomposite possesses higher donor density, enhanced conductivity and lower overpotential for dioxygen evolution. In addition, the nanocomposite demonstrates high photocatalytic activity for water oxidation to produce oxygen in a photoelectrochemical cell. The amount of O2 evolved from the optimized photoanode of the photoelectrochemical cell was 1.98 μmol in 2 h of simulated sunlight irradiation. This work demonstrates a facile synthesis of a novel nanocomposite as anode material for photocatalytic water oxidation to produce O2.

The comprehensive effects of visible light irradiation on silver nanowire transparent electrode

The silver nanowire (AgNW) transparent electrode is one of the promising components for flexible electronics due to its high electrical and thermal conductivity, optical transparency and flexibility. However, the application of the AgNW electrode with an improved performance is generally limited by its poor long-term stability. As the name suggests, the transparent electrode is usually exposed to visible light in various applications. Unlike other electrode materials, AgNWs show unique and complicated behavior under long-term visible light illumination. In this study, the comprehensive effect of visible light irradiation on the AgNW transparent electrode is initially investigated in detail. Light irradiation induces the migration of silver to enhance the nanowire contacts while also leading to the generation and growth of particles and diameter loss in the nanowire. Light irradiation accelerates the sulfidation and oxidation of the AgNWs as well, resulting in the emergence of degradation products on the nanowire surface. All these effects influence the sheet resistance of the AgNW electrode during light illumination. The light-induced change of sheet resistance also relates to the nanowire concentration due to the sensitivity of the wire–wire contact resistance near the percolation threshold. It is believed that this work will be a valuable reference for the design, processing and application of transparent electrodes used in numerous optoelectronic devices.

Carrier Transport of Silver Nanowire Contact to p-GaN and its Influence on Leakage Current of LEDs

The authors investigated the silver nanowires (AgNWs) contact formed on p-GaN. Transmission line model applied to the AgNWs contact to p-GaN produced near ohmic contact with a specific contact resistance (ρsc) of 10−1∼10−4 Ω·cm2. Noticeably, the contact resistance had a strong bias-voltage (or current-density) dependence associated with a local joule heating effect. Current-voltage-temperature (I-V-T) measurement revealed a strong temperature dependence with respect to ρsc, indicating that the temperature played a key role of an enhanced carrier transport. The local joule heating at AgNW/GaN interface, however, resulted in a generation of leakage current of light-emitting diodes (LEDs) caused by degradation of AgNW contact.

Stability of Schottky and Ohmic Au Nanocatalysts to ZnO Nanowires.

Manufacturable nanodevices must now be the predominant goal of nanotechnological research to ensure the enhanced properties of nanomaterials can be fully exploited and fulfill the promise that fundamental science has exposed. Here, we test the electrical stability of Au nanocatalyst-ZnO nanowire contacts to determine the limits of the electrical transport properties and the metal-semiconductor interfaces. While the transport properties of as-grown Au nanocatalyst contacts to ZnO nanowires have been well-defined, the stability of the interfaces over lengthy time periods and the electrical limits of the ohmic or Schottky function have not been studied. In this work, we use a recently developed iterative analytical process that directly correlates multiprobe transport measurements with subsequent aberration-corrected scanning transmission electron microscopy to study the electrical, structural, and chemical properties when the nanowires are pushed to their electrical limits and show structural changes occur at the metal-nanowire interface or at the nanowire midshaft. The ohmic contacts exhibit enhanced quantum-mechanical edge-tunneling transport behavior because of additional native semiconductor material at the contact edge due to a strong metal-support interaction. The low-resistance nature of the ohmic contacts leads to catastrophic breakdown at the middle of the nanowire span where the maximum heating effect occurs. Schottky-type Au-nanowire contacts are observed when the nanowires are in the as-grown pristine state and display entirely different breakdown characteristics. The higher-resistance rectifying I-V behavior degrades as the current is increased which leads to a permanent weakening of the rectifying effect and atomic-scale structural changes at the edge of the Au interface where the tunneling current is concentrated. Furthermore, to study modified nanowires such as might be used in devices the nanoscale tunneling path at the interface edge of the ohmic nanowire contacts is removed with a simple etch treatment and the nanowires show similar I-V characteristics during breakdown as the Schottky pristine contacts. Breakdown is shown to occur either at the nanowire midshaft or at the Au contact depending on the initial conductivity of the Au contact interface. These results demonstrate the Au-nanowire structures are capable of withstanding long periods of electrical stress and are stable at high current densities ensuring they are ideal components for nanowire-device designs while providing the flexibility of choosing the electrical transport properties which other Au-nanowire systems cannot presently deliver.

High conductive and scalable Ag nanowires flexible transparent electrode by nanowelding with physical methods

Transparent electrodes (TEs) are very important for electronic devices. At present, ITO is gaining the largest market share but will be reduced. Ag nanowires (AgNWs) TEs is acknowledged as one of the most potential alternative to ITO. However, AgNWs TEs still have electrical problems because of the low contact between the AgNWs. In this paper, we report three physics methods to increase the conductivity of AgNWs TEs by nanowelding the contact of nanowires. For heat-resistant materials, 200 °C heat-nanowelding can help to reduce the sheet resistance by 96.7%. For pressure resistant materials, 20MPa pressure-nanowelding can help to increase the conductivity by 98.7%. And the transmittance (>90%) remains constant during the above process. Yet, both of these methods cannot improve the adhesion between nanowires and the substrates. Luckily, tight adhesion can be obtained by overcoating a PEDOT: PSS lalyer on AgNWs film which can reduce the sheet resistance by 87.8%. This means that things are usually not perfect, and they have their own advantages and lay the foundation for the popularization and application of AgNWs TEs. In a word, these three nano-welding methods are all suit for manufacture on a large scale for high conductive AgNWs TEs.