I. Abstract of the Paper’s Core Research

This study independently formulated a specialized aerosol ink composed of cyclohexanone and terpineol combined with silver nanosheets. Using Optomec’s AJP high-precision printer, we fabricated micrometer-scale metallic grid‑type transparent conductive layers. We systematically investigated the effects of annealing temperature, printed film thickness, and grid line width/pore diameter on electrical and optical performance, and established a quantitative theoretical model relating transmittance to sheet resistance. The key findings are as follows:

• Silver nanosheets exhibit intrinsically high electrical conductivity, and low-temperature sintering enables the formation of a continuous conductive network.

The two-dimensional flake-like structures exhibit a contact area far greater than that of silver nanowires or nanoparticles, and ink deposition at room temperature already yields basic electrical conductivity. Inter-flake fusion sintering commences at 150°C, reaching electrical saturation at 175°C, with a maximum electrical conductivity of 1.1 × 10⁷ S/m, significantly reducing interfacial contact resistance.

• The aerosol coating features a high-precision, adjustable grid, achieving both 91% high light transmittance and low sheet resistance.

Precise control of line width at 125 μm, aperture size of 1.7 mm, and film thickness of 2.5 μm; the mesh fill factor is only 0.154, with a visible‑light transmittance of 91% and a sheet resistance as low as 4.6 Ω/sq, meeting commercial transparent electrode standards (transmittance ≥90%, sheet resistance ≤10 Ω/sq).

• Establish a grid-based photovoltaic performance prediction model

Derive the corresponding calculation formulas for aperture linewidth ratio, film thickness, transmittance, and sheet resistance, enabling pre‑simulation of target device parameters and significantly reducing experimental trial-and-error costs.

• Aerosol printing resolution far exceeds that of conventional inkjet devices.

Conventional inkjet printing achieves a minimum line width of 500 μm, enabling only large-aperture, low-transmittance grids. In contrast, AJP stably forms fine lines measuring 85–125 μm, and even with densely packed small‑aperture grids, it maintains high transmittance and excellent uniformity across the entire area.

• Flexibly adapts to stable films, with outstanding resistance to cracking under bending.

Silver nanosheet‑based two‑dimensional stacked films exhibit excellent stress‑dispersion performance; compared with silver nanoparticle films, they are less prone to cracking under bending and are compatible with flexible, transparent substrates such as PET, thereby meeting the long‑term durability requirements of wearable optoelectronic devices.

  II. Complete Process Flow for Fabricating Transparent Conductive Grids on Aerosol Substrates

1) Silver nanosheet powder is purified by centrifugation, and a specialized low-volatility ink suitable for aerosol applications is prepared using a formulation of cyclohexanone and terpineol.

2) Glass / PET transparent substrates undergo alkaline cleaning and nitrogen drying;

3) Ultrasonic atomization system: sheath gas flow rate of 90 SCCM, carrier gas flow rate of 17 SCCM, nozzle diameter of 150 μm, printing speed of 1 mm/s, and direct‑print periodic micron‑scale grids.

4) Annealing at a constant temperature of 200°C for 15 minutes completes the interfacial fusion and electrical conduction of the nanosheets.

5) Calibration has been completed using a white-light interferometer for film thickness measurement, a transmission scanner for transmittance measurement, and a four-point probe for sheet resistance measurement.

• Five Core Advantages of Aerosol-Based Processes (Comparison with Inkjet, Spin Coating, and Lithography)

Ultra-high line‑width printing precision, enabling high‑density, fine‑grained mesh.

Traditional inkjet printing achieves a minimum line width of 500 μm, requiring oversized apertures in the mesh; by contrast, AJP can reliably fabricate micro‑lines as narrow as 85–125 μm, enabling denser conductive pathways and lower sheet resistance at comparable light transmittance.

Ink system compatible with silver nanoplatelet two-dimensional materials

The atomized gas flow is gentle, preventing the fragmentation of the flaky nanostructure and fully preserving its large contact‑area advantage, thereby ensuring high intrinsic conductivity.

Digital grid-based freeform design, rapid iteration of optoelectronic parameters.

With CAD, line widths, hole diameters, and film thicknesses can be modified with a single click, and theoretical models enable rapid validation of the optimal high-transmittance, low-resistance solution, significantly shortening the R&D cycle.

Non-contact low-temperature forming, with no thermal damage to flexible plastics.

The print platform is set to only 90°C, with annealing up to a maximum of 200°C, ensuring that heat‑sensitive transparent substrates such as PET and PC do not deform or yellow.

Localized additive manufacturing saves precious metals and eliminates large‑area coating waste.

Silver material is deposited only in the grid‑line regions, reducing raw‑material waste by more than 70% compared with a full‑area spin‑coated metal film, thereby significantly lowering material costs.

III. Five Core Technological Innovations of This Study

Innovation 1: A specialized composite ink system for silver nanoplatelet aerosols

A dual-solvent system with high and low boiling points synergistically controls atomization and drying rates, addressing the challenges of agglomeration during atomization and nozzle clogging in flake‑shaped nanomaterials, thereby enabling stable, continuous printing of high‑quality conductive grid structures.

Innovative New Mechanism of Low-Temperature Fusion Sintering Between Two Layers

In situ TEM observations confirm that at 150°C, the edges of silver nanosheets undergo melt‑induced welding, forming a large‑area, continuous conductive pathway with a contact resistance far lower than that of silver nanowires or particle networks.

Innovative Three-Grid Photovoltaic Performance Quantitative Prediction Theoretical Model

A mathematical relationship among transmittance, sheet resistance, and line width/pore diameter/film thickness is established, enabling upfront simulation of device performance and eliminating the need for numerous repetitive process experiments.

Innovation 4: High-Precision AJP Mesh Breaks Through the Traditional Limits of Inkjet Performance

With micron‑scale fine patterning, it simultaneously achieves 91% high transmittance and a low sheet resistance of 4.6 Ω/sq, delivering overall performance that surpasses the values reported in most literature on silver‑based grid‑type transparent electrodes.

Innovative 5: Flexible, Crack-Resistant Two-Dimensional Silver Mesh Manufacturing Solution

The flake‑like stacked architecture effectively dissipates deformation‑induced stress, and the flexible substrate exhibits superior electrical stability under repeated bending compared to films composed of spherical silver nanoparticles, making it well suited for curved surfaces and wearable optoelectronic devices.

IV. Current Industry Challenges in the Process and Corresponding Breakthrough Solutions

Challenge 1: ITO—indium resources are scarce and it is highly brittle, making it unsuitable for flexible applications.

✅ Aerosol‑grown silver nanoplate metal mesh contains no indium, uses inexpensive raw materials, and features a flexible, bendable thin film, offering a complete replacement for ITO.

Challenge 2: Conventional inkjet-printed lines are thick, and high transparency cannot be achieved simultaneously with low electrical resistance.

✅AJP’s micron‑scale fine mesh achieves a balance between narrow line widths and large apertures, ensuring both excellent conductivity and high light transmittance—meeting two critical performance criteria.

Challenge 3: The interface resistance of silver nanowire/particle thin films is high, and annealing yields only limited performance improvements.

✅ Two-dimensional silver nanosheets offer an exceptionally large contact area; after low-temperature sintering, the conductive network remains continuous, resulting in a tenfold increase in electrical conductivity.

Challenge 4: Conventional coating and full‑sheet plating result in high precious‑metal consumption and persistently high costs.

✅ Aerosol‑based selective printing grid enables silver deposition only on functional traces, significantly reducing material consumption and making it ideal for large‑scale mass production.

Difficulty 5. The formulation lacks a mature simulation model, and the process relies entirely on trial-and-error development.

✅ A comprehensive formula for calculating optoelectronic performance has been established, enabling early simulation of the optimal grid size and significantly reducing the workload associated with sample preparation and testing.

V. Future Diversified Industrial Application Scenarios

1 Flexible Touch Screens and Foldable Display Panels

Curved and foldable devices lack ITO transparent touch electrodes, which are thin, lightweight, and bendable, thereby addressing the critical issue of ITO electrode fracture and failure.

2 Perovskite / Organic Flexible Photovoltaic Front Electrode

High-transmittance, low-resistance grid enhances light absorption and charge‑transport efficiency while reducing module manufacturing costs.

3 Wearable optoelectronic sensing patches for health monitoring

A transparent, flexible conductive layer that adheres to the skin for the acquisition of blood oxygen and photoplethysmographic physiological signals.

4 Automotive Curved Surface Transparent Electromagnetic Shielding Film

Car windows and curved center‑console components allow light to pass through while blocking radio‑frequency electromagnetic interference.

5 Laboratory Flexible Electronics R&D Platform

A desktop aerosol‑based system enables the rapid fabrication of transparent electrodes with tunable transmittance and electrical resistance, eliminating the need for costly vacuum‑coating equipment.

Image and Text Guide

Figure 1. Characterization of silver nanosheet materials and printed grid structures:

• A)   SEM image of silver nanosheets (AgNS) (scale bar: 1 μm): the nanosheets are polydisperse, with lengths ranging from 300 to 1000 nm and an average thickness of approximately 45 nm.
• B)   Transmission‑scanning optical image: aerosol‑jet‑printed grids of four different thicknesses (21, 38, 65, and 89 nm; scale bar, 3 mm). The red line on the 38‑nm grid indicates the location from which the C‑profile was extracted.
• C)   Centerline distance profile (vertical axis: 1−T; horizontal axis: Distance): A Gaussian fit is applied to the line shape, and the full width at half maximum (FWHM) yields the line width a. The aperture size b is obtained by subtracting the line width from the peak-to-peak spacing, serving to quantify the grid geometry.
• D)   Three-dimensional topography map obtained by white-light interferometry (WLI) with a thick grid (t ≈ 2.4 μm): enables non-destructive, rapid, and precise measurement of the thickness of printed features.

Figure 2. Sintering effect of annealing on silver nanoplatelet networks:

• A)   TEM images of two AgNS with edge-to-edge contact at room temperature (scale bar: 100 nm);
• B)   After annealing at 200 °C at the same location, sintering at the contact edge yields a large-area weld (scale bar: 100 nm), with a junction area of approximately 13,500 nm²—about seven times that of an AgNW junction with a 50-nm diameter (roughly 2,000 nm²).
• C)   SEM image of an AgNS network printed by water-based inkjet printing (scale bar: 500 nm);
• D)   After annealing at 200 °C, the nanosheets are clearly sintered into a continuous network (scale bar: 1000 nm), with sintered filaments up to approximately 250 nm in length visible between the network pores.
• E)   Under continuous heating at 50 °C, the network resistance decays exponentially with time and reaches saturation after approximately 15 minutes.
• F)   Variation of electrical conductivity with annealing temperature: Water-based ink (for inkjet printing) exhibits a steady increase from room temperature, reaching saturation at approximately 1.8 × 10⁷ S/m at 150–175 °C; C/T‑based ink used in AJP (cyclohexanone:terpineol = 90:10), due to residual high-boiling solvents, remains non-conductive below 150 °C and saturates at about 1.1 × 10⁷ S/m at 175 °C. In the remainder of this paper, all grids are uniformly fabricated using C/T‑ink via AJP printing and annealed at 200 °C for 15 minutes.

Figure 3. Effect of wire thickness on the electrical and optical properties of the mesh (with wire width a fixed at 85 μm and aperture b set to 1.15 mm):

• A)   Line width as a function of thickness: the line width in the x‑direction is (85 ± 4) μm, and in the y‑direction it is (69 ± 4) μm; the difference between the two arises from the non‑circular cross‑section of the AJP nozzle deposition. When the thickness exceeds 350 nm, residual high‑boiling‑point solvents cause the material to re‑disperse, leading to an increase in line width.
• B)   Grid square resistance R _S,G   As a function of the reciprocal of thickness, t⁻¹: dashed-line fit to R _S,G   = (σ _G ·t)⁻¹, yielding the grid conductivity σ _G   ≈ 3×10⁵ S/m (including contact resistance, approximately 1/30 of the single-wire conductivity);
• C)   Single-line conductance G _{S, L}   As a function of thickness: fitted G _{S, L}   = t·a·σ _L /L (L = 5.6 mm), yielding the linear conductivity σ _L   ≈ 4.7×10⁶ S/m;
• D)   Variation of the grid transmittance with thickness: Below the thickness‑independent conductivity limit (approximately 140 nm), the silver lines themselves exhibit non-zero transmittance, approaching unity; beyond this thickness, the transmittance stabilizes at 0.84 (corresponding to a fill factor FF = 0.154).

Figure 4. Influence of aperture size on mesh performance and the optimal device (with a fixed thickness t ≈ 200 nm and line width a ≈ 100 μm):

• A)   Photograph of the 8 distinct aperture grids on a microscope slide (scale bar: 1 cm), superimposed on the SEM image of the AgNS network to illustrate the transparency of the grids.
• B)   Transmittance as a function of b/a: in perfect agreement with the formula T ≈ [1 + 1/(b/a)]⁻² (red triangles = optimal grid);
• C)   The grid‑square resistance varies linearly with (1 + b/a), and the y‑intercept corresponds to the contact resistance R. _C   = 3.85 Ω (caused by the silver paste and contact tag), fitted to (σ _L ·t)⁻¹ = 0.43 Ω/sq, corresponding to σ _L   ≈ 1.2×10⁷ S/m;
• D)   Transmittance and R after correcting the contact resistance _S,G   the relationship (fitted by eq. 3, σ _L   ≈ 1.3×10⁷ S/m): optimal mesh T = 87%, R _S,G   = 7.12 Ω; the blue box indicates T ≥ 90% and R _S,G   Target area with a resistance of ≤ 10 Ω/sq;
• E)   Literature comparison of printed grids made from different nanomaterials: The performance of AgNS grids is consistent with the trend observed for continuous AgNW networks and outperforms AgNP grids (including those coated with PEDOT:PSS, CNTs, or ITO).