Air-Stable Imine N-Dopants for Organic Solar Cells
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Solution Overview
Problem
Current organic solar cells (OSCs) face challenges with the stability and availability of air-stable n-dopants, which are essential for high efficiency and reproducibility, particularly in mass production, as strong redox n-dopants tend to degrade easily when exposed to atmospheric oxygen.
Innovation Solution
Development of compounds with a specific structural moiety comprising a conjugated system of delocalized electrons, where imine functional groups are used as n-dopants, providing high stability and conductivity, and can be processed under various conditions including vacuum or in air, with the ability to form stable n-doped layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If strong redox n-dopants are used to achieve high conductivity and efficient n-doping, then the doping efficiency and conductivity are improved, but the stability of the dopant deteriorates due to easy degradation by atmospheric oxygen
Solution Approach 1:
The patent changes the chemical parameters of the dopant by introducing electron-withdrawing groups (such as fluorine atoms) and modifying the molecular structure to achieve a balance between reducing strength and air stability. This allows the dopant to maintain sufficient electron-donating capability while being less susceptible to oxidation by atmospheric oxygen.
Solution Approach 2:
The patent employs composite molecular structures combining electron-donating moieties with electron-withdrawing groups. This composite approach creates a dopant that has both the necessary reducing power for efficient n-doping and enhanced stability against atmospheric oxidation, resolving the contradiction between doping efficiency and air stability.
2Stability of the object's composition
If air-stable precursor compounds are used to improve stability, then the air stability is improved, but the doping strength deteriorates compared to strong redox dopants
Solution Approach 1:
The patent modifies the molecular parameters of air-stable precursors by introducing stronger electron-withdrawing groups and adjusting the conjugation system to enhance the electron-donating ability. This allows the dopant to maintain air stability while achieving sufficient doping strength for practical applications.
Solution Approach 2:
The patent uses the compound as an intermediary that can function both as an air-stable precursor and as an effective n-dopant. The molecular structure acts as a mediator between the requirements for air stability and doping strength, enabling the substance to fulfill both roles simultaneously under appropriate conditions.
3Device complexity
If simple device structures are used to reduce complexity, then the device complexity is reduced, but the efficiency deteriorates without interfacial injection layers
Solution Approach 1:
The patent employs compounds that can serve multiple functions: they act as electron transport materials, n-dopants, and interfacial injection layer components simultaneously. This multi-functionality allows simple device structures to achieve high efficiency without requiring separate interfacial injection layers, as the electron transport material itself provides the necessary charge injection capability.
Solution Approach 2:
The patent merges the functions of electron transport and charge injection by using doped electron transport materials that inherently provide both electron transport capability and efficient charge injection at interfaces. This consolidation eliminates the need for separate interfacial injection layers while maintaining or improving device efficiency.
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 compounds achieve high conductivity in the range of 10−2-10−6 S/cm, allowing for efficient n-doping of electron transport matrices, enhancing the stability and performance of OSCs while maintaining air stability and ease of processing.
Implementation Method 1
The compounds achieve high conductivity in the range of 10−2-10−6 S/cm, allowing for efficient n-doping of electron transport matrices
Implementation Method 2
A is a structural moiety that consists of at least two atoms and comprises a conjugated system of delocalized electrons
Data Source
AI summary
The invention relates to an electronic device comprising a compound having Formula (1): ABx (1), wherein A is a structural moiety that consists of at least two atoms and comprises a conjugated system of delocalized electrons, each B is independently selected from an imine functional group (1a), wherein R1, R2, R3, R4 are independently selected from C1-C30 alkyl, C2-C30 alkenyl, C2-C3 alkinyl, C3-C30 cycloalkyl, C6-C30 aryl, C2-C30 heteroaryl, C7-C30 arylalkyl, C3-C30 heteroarylalkyl, the wave line represents a covalent bond to the imine nitrogen atom, G is in each group (1a) independently selected from a quarternary carbon atom and from a cyclopropenylidene structural moiety, x is an integer equal one or higher, preferably equal two or higher, and the lone electron pair of the imine nitrogen atom and/or the pi-electrons of the imine double bond of at least one group B is conjugated with the conjugated system of delocalized electrons comprised in the structural moiety A, with the proviso that two or more of the substituents R1, R2, R3, R4 may be connected to form a ring that may contain also unsaturation and, if any of the substituents R1, R2, R3, R4 comprises two or more carbon atoms, up to one third of the overall count of the carbon atoms in the substituent or in any ring formed by two connected substituents can be replaced with heteroatoms independently selected from O, S, N and B as well as to an electrically semiconducting material and a compound for use in the electronic device.