Indium-less Optically Porous Metalized Layers
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Solution Overview
Problem
Indium tin oxide (ITO) faces economic and performance challenges due to the high cost of indium, brittle nature, and inefficiency in flexible electronic applications, along with expensive deposition methods and low light transmission in OLEDs.
Innovation Solution
A metalized surface with an array of openings is used, created through a print-and-plate process, to form a thin, optically porous and conductive layer that allows light transmission and electrical conductivity, replacing traditional ITO layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional ITO layers are used to achieve electrical conductivity and transparency, then conductivity and transparency are achieved, but cost increases due to precious indium metal and expensive vacuum sputtering deposition
Solution Approach 1:
The patent applies porous materials by using a metal layer with an array of openings (optically porous structure) instead of solid ITO. The metal layer has controlled porosity that allows light transmission while maintaining electrical conductivity through the metal matrix, achieving the desired optical and electrical properties at lower cost
Solution Approach 2:
The patent uses composite materials by combining a metal base layer with an array of openings to create a composite structure that exhibits both metallic conductivity and optical transparency. This composite approach replaces the homogeneous ITO material with a structured metal-O2 composite that achieves similar functionality at lower cost
2Reliability
If solid ITO layers are deposited to provide electrical conductivity, then conductivity is achieved, but flexibility deteriorates due to the brittle nature of ITO
Solution Approach 1:
The porous metal layer structure provides flexibility by creating a network of interconnected metal elements separated by openings. This porous architecture allows the layer to bend and deform without fracturing, unlike solid brittle ITO, while maintaining continuous electrical pathways through the metal matrix
Solution Approach 2:
The patent employs flexible shells and thin films by using a thin metal layer with controlled thickness and porous structure. This thin-film approach with openings enables the conductive layer to conform to flexible substrates and withstand bending stresses that would cause solid ITO to fracture
3Reliability
If ITO layers are used in OLED applications to achieve conductivity, then electrical function is achieved, but light transmission efficiency deteriorates due to light trapping in the ITO layer
Solution Approach 1:
The optically porous metal layer dramatically improves light transmission efficiency by providing direct optical pathways through the array of openings. Light can pass through the openings without being trapped or reflected by the metal, achieving transmission efficiency that exceeds traditional solid ITO layers while maintaining electrical conductivity through the metal matrix
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution reduces costs, improves performance, and enhances manufacturability by achieving high light transmission and conductivity with a thinner, more flexible metal layer, comparable to or exceeding ITO's efficiency.
Implementation Method 1
heating or otherwise processing the substrate to a temperature that releases or activates the catalyst dissolved therein
Implementation Method 2
immersing the substrate with the dried or cured catalyst material pattern in an electroless copper plating bath, which deposits a thin layer of copper on the substrate surface only where there is dried catalytic material
Implementation Method 3
This thin layer of metal has a dense array of openings that allow the majority of light to pass therethrough. This transparent or 'optically porous' metal film
Data Source
AI summary
Thin indium-less “optically porous” layers adapted to replace traditional ITO layers are provided herein. A thin metalized film adapted to carry an electrical charge can include a dense pattern of small openings to allow the transmission of light to or from an underlying semiconductor material. The pattern of openings can create a regular or irregular grid pattern of low aspect ratio fine-line metal conductors. Creation of this optically porous metalized film can include the printing of a catalytic precursor material, such as palladium in solution in a pattern on a substrate, drying or curing the catalytic precursor, and the deposition of a thin layer of metal, such as copper on the dried precursor to form the final conductive and optically porous film.