Siloxane Matrix Dopant Ink for Solar Cell Fabrication
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Solution Overview
Problem
Dopant inks used in solar cell fabrication often experience out-gassing issues, leading to difficulties in achieving precise control over diffusion profiles and increasing costs due to the need for tight temperature control and additional processing steps, especially when both n-type and p-type dopants are required in different regions of the substrate.
Innovation Solution
The development of dopant ink compositions that integrate dopants or dopant precursors into a bound state within a siloxane matrix, which undergoes cross-linking reactions at elevated temperatures or with UV light to form a silicon oxide matrix, reducing vapor pressure and out-gassing, and incorporating dopants within nanoparticles to enhance retention mechanisms at various temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dopant inks are used in solar cell fabrication, then doping can be achieved, but out-gassing occurs leading to imprecise diffusion profiles and increased costs
Solution Approach 1:
The patent uses a siloxane matrix composite material that binds dopant atoms within its structure. The siloxane backbone with oxygen atoms provides binding sites for dopants, creating a composite system where the matrix prevents dopant out-gassing while enabling controlled release during processing. This composite structure resolves the contradiction by maintaining doping capability while eliminating harmful out-gassing.
Solution Approach 2:
The patent changes the chemical state of dopants from free/loosely-bound to tightly-bound within the siloxane matrix structure. By modifying the binding parameters and thermal stability of the dopant-matrix interaction, the system transitions from a state prone to out-gassing to one where dopants are retained until intentional release at controlled temperatures, thereby improving diffusion profile precision.
2Reliability
If tight temperature control is implemented to prevent out-gassing, then dopant retention improves, but manufacturing complexity and costs increase
Solution Approach 1:
The siloxane matrix provides self-service by inherently binding and retaining dopant atoms through its chemical structure without requiring external temperature control systems. The matrix's oxygen atoms naturally bind dopants, and the cross-linked network structure provides thermal stability, eliminating the need for complex active temperature management while maintaining reliable dopant retention.
Solution Approach 2:
The patent changes the thermal stability parameter of the dopant system by incorporating it into the thermally stable siloxane matrix structure. This parameter change allows the system to maintain dopant retention at higher temperatures without requiring tight temperature control, thereby reducing manufacturing complexity while improving reliability.
3Manufacturing precision
If additional processing steps are added to control out-gassing, then doping precision improves, but manufacturing efficiency decreases
Solution Approach 1:
The patent merges the dopant delivery function and the out-gassing prevention function into a single integrated siloxane matrix system. The matrix simultaneously serves as the dopant carrier, the retention mechanism, and the controlled release system, eliminating the need for separate processing steps while maintaining high doping precision and improving manufacturing efficiency.
Solution Approach 2:
The siloxane matrix exhibits multi-functionality by simultaneously providing dopant binding, thermal stability, controlled release, and diffusion control. This universal system replaces multiple specialized processing steps, thereby improving manufacturing efficiency while maintaining or enhancing doping precision through the matrix's inherent properties.
4Object-generated harmful factors
If dopants are incorporated into siloxane matrix, then out-gassing is reduced, but additional processing steps are required for cross-linking
Solution Approach 1:
The patent utilizes phase transitions and chemical transformations of the siloxane matrix during processing. The matrix undergoes cross-linking reactions at elevated temperatures or with UV light, transitioning from a precursor state to a cured network state. This phase transition integrates the cross-linking step into the existing thermal processing workflow, reducing the need for separate additional processing steps while effectively preventing dopant out-gassing.
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 reduces dopant out-gassing, allows for more precise control over doping profiles, and decreases manufacturing costs by eliminating the need for additional processing steps and expensive equipment, while enabling efficient delivery of both n-type and p-type dopants to specific regions of the substrate.
Implementation Method 1
a cross-linkable matrix precursor, a bound dopant species, and a solvent... undergoes cross-linking reactions at elevated temperatures or with UV light to form a silicon oxide matrix
Implementation Method 2
undergoes cross-linking reactions at elevated temperatures or with UV light to form a silicon oxide matrix
Implementation Method 3
The method also includes heating the dopant ink composition to a temperature between about 100° C. and about 400° C. for a time period between about 1 minute and about 30 minutes to remove a substantial portion of a solvent of the dopant ink composition
Implementation Method 4
driving dopants from the cured dopant ink composition toward the substrate
Data Source
AI summary
Dopant ink compositions and methods of fabricating solar cells there from are described. A dopant ink composition may include a cross-linkable matrix precursor, a bound dopant species, and a solvent. A method of fabricating a solar cell may include delivering a dopant ink composition to a region above a substrate. The dopant ink composition includes a cross-linkable matrix precursor, a bound dopant species, and a solvent. The method also includes baking the dopant ink composition to remove a substantial portion of the solvent of the dopant ink composition, curing the baked dopant ink composition to cross-link a substantial portion of the cross-linkable matrix precursor of the dopant ink composition, and driving dopants from the cured dopant ink composition toward the substrate.