Angled Substrate Coating for Defect-Tolerant Solar Devices
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Solution Overview
Problem
Existing methods for fabricating thin film solar devices and OLEDs are limited by material defects such as pinholes and material spits due to high-speed deposition processes, which restrict throughput and increase costs, and require high-temperature deposition of transparent conductors, limiting substrate options and device costs.
Innovation Solution
A method using a structured substrate with integral faces at angled positions and a cavity, where non-contacting inter-digitated conductors are deposited using off-axis directional vacuum coating, allowing for the insertion or extraction of charge through conducting layers, and the use of nano particles for ohmic contacts, enabling flexible coating schemes and reducing material requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-speed deposition processes are used in roll-to-roll systems, then productivity is improved, but material defects such as pinholes and material spits occur
Solution Approach 1:
The patent applies local quality by creating non-uniform coating thickness intentionally. The coating is designed to be thicker in certain areas (ridges) and thinner in others (valleys), which allows the system to tolerate pinholes and defects without compromising overall device performance. This local variation in coating quality resolves the contradiction by making the system insensitive to material defects while maintaining high-speed deposition.
Solution Approach 2:
The patent introduces a new dimension by using three-dimensional structured substrates with varying heights and angles instead of flat substrates. This dimensional change creates shadowing effects during deposition, allowing selective coating of different surfaces. The angular faces at different orientations enable the coating process to deposit material in a controlled manner that tolerates high-speed processing defects.
2Reliability
If transparent conductors require higher temperature deposition, then electrical performance is improved, but substrate selection is limited and device cost increases
Solution Approach 1:
The patent changes the deposition temperature parameter by using low-temperature deposition processes for transparent conductors. Instead of requiring high temperatures, the invention achieves acceptable electrical performance at lower temperatures, which expands substrate selection to include materials that cannot withstand high heat. This parameter change resolves the contradiction between electrical performance and substrate versatility.
3Reliability
If uniform coating is required for deposited materials, then device performance is maintained, but process control complexity and cost increase
Solution Approach 1:
The patent inverts the traditional approach by not requiring uniform coating. Instead of making the coating uniform to achieve performance, the invention achieves performance despite non-uniform coating by using three-dimensional structures where different regions serve different functions. This inversion resolves the contradiction by eliminating the need for complex process control while maintaining device performance.
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 approach enables high-speed, low-cost manufacturing with improved fabrication yields and reduced material costs, as it allows for non-uniform coating and eliminates short-circuiting issues, while maintaining device performance by using structured substrates and selective coatings.
Implementation Method 1
non-contacting inter-digitated conductors are deposited using off-axis directional vacuum coating
Data Source
AI summary
A method of producing a structure comprising a substrate (11) having at least one integral first face at a first angle relative to a normal from the substrate, at least one second integral second face at a second angle relative to a normal from the substrate; with a cavity in the structure between the first and second faces; the method comprising the steps of: coating a portion (15) of the first face with a first conducting layer; coating a portion (18) of the second face with a second conducting layer; and depositing in the cavity an active material (31) to provide ohmic and rectifying contacts for insertion or extraction of charge from the active material by way of the first and second conducting layers. The active material may be photovoltaic, light emitting or ion conducting.