Photovoltaic Cell Macromolecular Active Layer Excitation Energy
Solution Overview
Problem
Photovoltaic cells with organic layers containing macromolecular compounds do not have satisfactory short-circuit current density and photoelectric conversion efficiency.
Innovation Solution
A photovoltaic cell comprising a first and second electrode with an active layer containing a macromolecular compound having a specific structural unit, where the inverse of the excitation energy from the ground singlet state to the lowest excited singlet state is calculated using time-dependent density functional theory to be 0.43 (eV−1) or more, enhancing light absorption and photoelectric conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a macromolecular compound comprising repeated units (A) and (B) is used in the organic layer, then the device complexity is reduced and manufacturing is simplified, but the short-circuit current density and photoelectric conversion efficiency are insufficient
Solution Approach 1:
The patent applies parameter changes by precisely controlling the molecular structure of the macromolecular compound, specifically setting the inverse of excitation energy to 0.43 eV⁻¹ or more. This parameter optimization enables the material to absorb light with wavelengths of 600 nm or more, thereby improving photoelectric conversion efficiency while maintaining the simplified manufacturing process of organic thin film solar cells
Solution Approach 2:
The patent uses composite materials by combining specific structural units (Formula 1) with trivalent aromatic hydrocarbon groups or trivalent heterocyclic groups. This composite molecular structure achieves both the desired optical properties for high efficiency and the processability required for easy manufacture through coating processes
2Use of energy by moving object
If the inverse of excitation energy is increased to 0.43 (eV−1) or more, then light absorption at longer wavelengths is enhanced, but the molecular structure complexity increases
Solution Approach 1:
The patent optimizes the excitation energy parameter to achieve an inverse value of 0.43 eV⁻¹ or more, which corresponds to light absorption at wavelengths of 600 nm or more. This parameter control enhances energy utilization while the patent manages structural complexity through defined repeating units with specific functional groups
Solution Approach 2:
The patent segments the macromolecular compound into repeating units with specific structures (Formula 1), where Ar1 and Ar2 represent trivalent aromatic hydrocarbon groups or trivalent heterocyclic groups. This segmentation allows systematic optimization of the excitation energy parameter while maintaining a manageable molecular structure through repetition of standardized units
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 photovoltaic cell achieves a high short-circuit current density and photoelectric conversion efficiency due to the macromolecular compound's ability to absorb light with a longer wavelength, resulting in improved energy conversion.
Implementation Method 1
the inverse of excitation energy of the macromolecular compound from a ground singlet state to a lowest excited singlet state that is calculated using a time-dependent density functional theory is 0.43 (eV−1) or more
Implementation Method 2
a photovoltaic cell comprising: a first electrode; a second electrode; an active layer positioned between the first electrode and the second electrode
Data Source
AI summary
The present invention provides a photovoltaic cell having a large short-circuit current density and a large photoelectric conversion efficiency.This photovoltaic cell comprises:a first electrode;a second electrode;an active layer between the first electrode and the second electrode;wherein the active layer contains a macromolecular compound having a structural unit represented by Formula (1):wherein Ar1 and Ar2 are the same as or different from each other and represent a trivalent aromatic hydrocarbon group or a trivalent heterocyclic group; X1 and X2 are the same as or different from each other and represent —O—, —S—, —C(═O)—, —S(═O)—, —SO2—, —C(R50)(R51)—, —Si(R3)(R4)—, —N(R5)—, —B(R6)—, —P(R7)—, or —P(═O)(R8)—; R50, R51, R3, R4, R5, R6, R7, and R8 are the same as or different from each other and represent a hydrogen atom, a halogen atom, or a monovalent organic group; and X1 and Ar2 are bonded with atoms adjacent to each other on a ring that constitutes Ar1, and X2 and Ar1 are bonded with atoms adjacent to each other on a ring that constitutes Ar2,wherein an inverse of the excitation energy of the macromolecular compound from a ground singlet state to a lowest excited singlet state that is calculated using the time-dependent density functional theory is 0.43 (eV−1) or more.