Organic Semiconductor Additive for Phase-Separation Control
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Solution Overview
Problem
Organic solar cells using conjugated polymers have lower photoelectric conversion efficiency compared to inorganic semiconductors, and existing additives like 1,8-diiodooctane pose challenges due to high boiling point, slow drying, and environmental concerns, making it difficult to achieve high efficiency and stability while maintaining processing properties.
Innovation Solution
An organic semiconductor composition comprising an electron donating and accepting organic semiconductor, a solvent, and an additive with a higher boiling point than the solvent, specifically selected compounds represented by formulae (1) to (3), which enhance the affinity and dispersibility of the electron accepting organic semiconductor, improving phase-separation structure and photoelectric conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If 1,8-diiodooctane is used as an additive to improve photoelectric conversion efficiency, then phase-separation structure is improved, but drying time increases and environmental impact worsens
Solution Approach 1:
The patent changes the chemical structure parameters of the additive by replacing the halogenated carbon chain structure of 1,8-diiodooctane with a carboxylic acid structure (specifically octanoic acid and its derivatives). This parameter change maintains the ability to improve phase-separation structure while reducing boiling point and improving environmental compatibility.
Solution Approach 2:
The patent adopts carboxylic acid additives that are more environmentally friendly and easier to decompose compared to persistent halogenated compounds. These additives serve their function during manufacturing and processing, then can be removed or degraded without long-term environmental harm.
2Stability of the object's composition
If a solvent with high affinity for electron accepting organic semiconductor is used, then dispersibility improves, but boiling point becomes excessively high
Solution Approach 1:
The patent uses carboxylic acid additives as intermediary substances that mediate between the solvent and the electron accepting organic semiconductor. These additives enhance the affinity and dispersibility of the semiconductor in the solvent without requiring the solvent itself to have excessively high boiling point.
Solution Approach 2:
The patent changes the approach from modifying solvent properties (high boiling point) to modifying additive properties (carboxylic acid structure). This allows achieving good dispersibility through the additive's chemical interaction rather than relying on solvent boiling point.
3Manufacturing precision
If conventional inorganic semiconductors are used for photovoltaic elements, then photoelectric conversion efficiency is high, but manufacturing cost increases
Solution Approach 1:
The patent changes the material parameter from inorganic semiconductor to organic semiconductor, enabling solution-based processing. Combined with carboxylic acid additives, this allows achieving high photoelectric conversion efficiency through low-cost organic materials and simplified manufacturing processes.
Solution Approach 2:
The patent replaces the mechanical/thermal processing required for inorganic semiconductors (high temperature, vacuum conditions) with chemical solution processing. The carboxylic acid additives enable this substitution by facilitating proper phase-separation and film formation during solution drying.
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
The composition achieves high photoelectric conversion efficiency while providing excellent processing properties and a low environmental impact by controlling the phase-separation structure and aggregation of the electron accepting organic semiconductor, leading to improved photovoltaic performance.
Implementation Method 1
the phase-separation structure is affected by affinity/repulsive properties among the electron donating organic semiconductor, the electron accepting organic semiconductor, a solvent and an additive
Implementation Method 2
excessive aggregation of the electron accepting organic semiconductor or the like easily occurs in the process in which the organic semiconductor composition is dried/condensed after applying a solution
Data Source
AI summary
A photovoltaic element has high photoelectric conversion efficiency as well as excellent processing properties/low environmental load. The organic semiconductor composition includes as an additive a compound in which one or two aromatic rings are substituted with a predetermined number of alkyl groups, alkoxy groups, alkanoyl groups, or thioalkyl groups. There is also a method of manufacturing a photovoltaic element which uses the composition.