Transparent Metal Mesh Electrodes Microfabricated by Structuring Water-Soluble Polymer Resist via Laser Ablation

Abstract

We present a method of manufacturing semitransparent mesh-shaped electrodes using laser structuring of a polymer followed by resistive thermal evaporation of a metallic layer. Toluene, used for preparing a polymer solution and its layer deposition, has been replaced with ethanol, thus eliminating a hazardous solvent from the process. The influence of adding photosensitizers to the polymer base on the structuring laser ablation threshold has been investigated, with most prominent reduction from 1.3 to ∼0.3 W for a UV laser line irradiation. Finally, and most importantly, the key step of this method, the development step that includes the removal of a resist, was carried out in water, thus ruling out completely other environmentally hazardous solvents from the process. Additionally, it does not require cleanroom conditions. The final electrode prototype was tested in electro- and thermomodulation measurements, proving its usefulness in spatial control of electric field and heat generation. Consequently, our work paves the way for other applications requiring patterned semitransparent electrodes made in a sustainable process.

Crack-Templated Wire-Like Semitransparent Electrodes with Unique Irregular Patterns

“…The manufactured electrode is presented in Figure 3 a and compared to the classical mesh-shaped semitransparent electrode 13 ( Figure 3 b). The electrode obtained by inducing cracks in the polymer mask is characterized by unique shapes.…”

“…Regular shapes such as mesh-shaped patterns are very common in the context of transparent electrodes and can be manufactured using many different methods, usually with tunable line width and spacing. − Polygons, circles, , and other regular shapes always require predesign to plan the movement of the printer head, laser head, or other device used in the method or, in the case of photolithography, to make the mask. Regular shapes have the advantage easily predicted TE mechanisms of action due to the simple design that can be simulated.…”

Direct Laser Writing: From Materials Synthesis and Conversion to Electronic Device Processing

“…[92] If not properly controlled, high laser power can also lead to evapora-tion, sublimation, and ablation of irradiated materials, which in some cases is the desirable outcome for patterning. [33,111] In other cases, it can be an undesirable outcome, that indicates that excessive laser energy degraded the chemical or physical process being targeted. Hence, most process-property optimization methods report the outcomes or irradiation within power intervals against another variable of interest (e.g., writing speed, repetition frequency) to determine processing windows.…”

“…For SDLW, the purpose is only to shape the geometry and architecture of solid materials with pre-defined properties and functions. [31][32][33][34] This is fundamental for several processes, including geometry definition in micromachining, but also in cutting processes used for mask manufacturing or via hole establishment. [27,35] However, other techniques must be used to synthesize and deposit materials with pre-determined properties, also generating ablation waste.…”

Unleashing the Power of Quantum Dots: Emerging Applications from Deep‐Ultraviolet Photodetectors for Brighter Futures

“…As UWBG TCOs have been newly reported, new transparent electrode candidates for DUV PD are increasing. As another alternative, transparent electrodes providing structure permeability, such as mesh‐type metal electrodes [ 156,157 ] or metal nanowire networks, could also be considered. [ 158,159 ] These types of electrodes have advantages in transparency and potential for flexible electronics. 2)The stability issues in the QDs film: Most QDs have a large number of defects on the surface, which cause a decrease in the long‐term stability of the QDs film.…”