Organic Modulation Element for Solar Cell Light Control
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Solution Overview
Problem
Existing wavelength conversion films in solar cells are limited in their ability to modulate input light effectively, as they primarily convert short-wavelength light to long-wavelength light without the capability to purposefully adjust the input light according to specific requirements.
Innovation Solution
An organic modulation element comprising an organic modulation layer with organic semiconductor molecules that enable reverse intersystem crossing from a lowest excited triplet state to a lowest excited singlet state, along with a first electrode and a second electrode, allowing for the modulation of input light through charge separation and light emission control via applied voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional wavelength conversion film is used, then light conversion from short wavelength to long wavelength is achieved, but the ability to modulate input light according to specific requirements is insufficient
Solution Approach 1:
The patent applies parameter changes by carefully controlling the rate constants of intersystem crossing (kISC), reverse intersystem crossing (kRISC), and non-radiative deactivation (kTnr) in the organic semiconductor molecules. By adjusting these kinetic parameters, the system achieves both high light modulation capability through triplet state accumulation and maintains high photoelectric conversion efficiency, resolving the technical contradiction between adaptability and reliability
2Adaptability or versatility
If the intersystem crossing rate constant is increased to enhance charge separation, then light modulation capability improves, but non-radiative deactivation may increase reducing efficiency
Solution Approach 1:
The patent resolves this contradiction by precisely controlling the kinetic parameters of the organic semiconductor molecules. The conditions kISC > kRISC and kRISC > kTnr are established to ensure that while intersystem crossing efficiently populates the triplet state for charge separation, the reverse crossing and deactivation pathways are kept sufficiently slow to maintain high quantum efficiency. This parameter optimization enables both effective charge separation and minimal energy loss
Solution Approach 2:
The patent utilizes the dynamic behavior of triplet states in organic semiconductor molecules, where the triplet state lifetime is extended through controlled reverse intersystem crossing. This dynamic approach allows the system to accumulate triplet states for effective charge separation while maintaining the ability to modulate light output by controlling the population of these long-lived triplet states, thereby achieving both high adaptability and energy 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 organic modulation element effectively modulates input light by enhancing charge separation efficiency and suppressing deactivation, thereby improving photoelectric conversion efficiency and allowing for purposeful adjustment of light emission.
Implementation Method 1
an organic modulation element capable of modulating input light... improving photoelectric conversion efficiency
Implementation Method 2
an excited state enabling reverse intersystem crossing from a lowest excited triplet state to a lowest excited singlet state in each of the plurality of organic semiconductor molecules is formed due to irradiation with the input light
Data Source
AI summary
Provided is an organic modulation element including an organic modulation layer containing a plurality of organic semiconductor molecules, a first electrode, and a second electrode. Each of the plurality of organic semiconductor molecules is a molecule in which an excited state enabling reverse intersystem crossing from a lowest excited triplet state to a lowest excited singlet state is formed due to irradiation with the input light. In each of the plurality of organic semiconductor molecules, an intersystem crossing rate constant from the lowest excited singlet state to the lowest excited triplet state is greater than a reverse intersystem crossing rate constant from the lowest excited triplet state to the lowest excited singlet state, and the reverse intersystem crossing rate constant from the lowest excited triplet state to the lowest excited singlet state is greater than a non-radiative deactivation rate constant from the lowest excited triplet state to a ground state.