Organic Material for Photoelectric Conversion Element
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic thin film solar cells face challenges in achieving high open circuit voltage, wide wavelength light absorption, and efficient charge transport due to limitations in exciton diffusion length and charge transportation in conventional materials.
Innovation Solution
A novel organic material represented by General Formula (1) with specific alkyl and aromatic groups is developed, which forms an aggregated structure for improved solubility and charge transport, combined with a n-type organic material to create a bulk heterojunction structure for enhanced photoelectric conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conjugated polymers are used as p-type semiconductor material, then charge separation ability and charge transport ability are improved, but open circuit voltage is reduced due to low ionization potential
Solution Approach 1:
The patent changes the molecular structure parameters of the p-type semiconductor from conventional conjugated polymers to low-molecular-weight compounds with specific functional groups (diketopyrrolopyrrole core with electron-donating substituents). This structural parameter change increases ionization potential while maintaining charge transport capability through molecular design, directly resolving the contradiction between open circuit voltage and charge transport ability.
2Ease of manufacture
If organic materials are used in solar cells, then manufacturing cost is reduced and ease of manufacture is improved, but photoelectric conversion efficiency is reduced due to short exciton diffusion length
Solution Approach 1:
The patent creates a composite bulk heterojunction structure by combining the newly developed p-type low-molecular-weight semiconductor with n-type semiconductor materials. This composite structure provides both efficient exciton separation at the pn interface and adequate charge transport paths, achieving high photoelectric conversion efficiency while maintaining the manufacturing advantages of organic materials through solution processing.
3Ease of manufacture
If low-molecular-weight organic materials are used, then manufacturing simplicity is improved, but aggregated structure for charge transport is insufficient
Solution Approach 1:
The patent introduces specific functional groups (such as alkyl chains and aromatic hydrocarbon groups) as intermediary structures that mediate between the molecular core and the surrounding environment. These intermediary groups promote self-assembly into aggregated structures with ordered arrangements that facilitate charge transport, while the materials remain processable by simple coating methods without vacuum equipment.
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 novel organic material achieves a high open circuit voltage, wide wavelength light absorption, and improved charge transport, leading to increased photoelectric conversion efficiency in organic thin film solar cells.
Implementation Method 1
it can absorb light of a wide wavelength range
Implementation Method 2
Excitons generated in the p-type semiconductor and/or the n-type semiconductor by light absorption are dispersed to a pn interface, and then, are separated into electrons and holes at the pn interface
Implementation Method 3
by ensuring the charge transport path, the electric charge can be transferred to each of the electrode without binding them each other during transportation
Data Source
AI summary
An organic material represented by the following General Formula (1):where in the General Formula (1), R1 and R2, which may be identical to or different from each other, each represent an alkyl group having 4 to 24 carbon atoms, X represents a substituted or unsubstituted aromatic hydrocarbon group, Y represents an aromatic hydrocarbon group, an alkoxyl group, or an alkyl group, which may be substituted with a substituent, and n represents an integer of 1 to 3.