Perovskite-Quantum Dot Light Absorption Layer for Solar Cells
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Solution Overview
Problem
Conventional photoelectric conversion elements, such as quantum dot and perovskite solar cells, face challenges in achieving both high durability and high photoelectric conversion efficiency, particularly in the near-infrared light region, due to surface oxidation of quantum dots and moisture sensitivity of perovskite compounds.
Innovation Solution
A light absorption layer comprising a perovskite compound with a band gap energy of 1.7 eV or more and 4.0 eV or less, combined with quantum dots having a band gap energy equal to or more than 0.2 eV and equal to or less than the perovskite compound's, enhances durability and photoelectric conversion efficiency by stabilizing the crystal structure and reducing carrier deactivation sites.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If quantum dots are used as light absorption material, then photoelectric conversion efficiency in near-infrared region is improved, but durability deteriorates due to surface oxidation
Solution Approach 1:
The patent combines quantum dots with perovskite compounds to form a composite light absorption layer. The perovskite compound acts as a protective matrix that prevents surface oxidation of quantum dots while maintaining their photoelectric conversion efficiency in the near-infrared region.
Solution Approach 2:
The perovskite compound serves as an intermediary protective layer between the quantum dots and the oxidizing atmosphere. It physically isolates the quantum dot surface from oxygen and moisture, preventing oxidation without interfering with light absorption and charge transfer processes.
2Reliability
If perovskite compound is used as light absorption material, then durability is improved, but photoelectric conversion efficiency deteriorates due to moisture decomposition
Solution Approach 1:
The patent creates a composite structure where perovskite compounds are combined with quantum dots. The quantum dots provide high photoelectric conversion efficiency while the perovskite matrix provides durability, and their combination yields synergistic effects that protect against moisture decomposition.
Solution Approach 2:
The perovskite compound creates a protective environment around the quantum dots that is inert to moisture and oxygen. This protective matrix effectively isolates the sensitive quantum dot surfaces from harmful atmospheric components, preventing decomposition and oxidation.
3Reliability
If halogen composition is replaced with bromine from iodine, then durability improves, but photoelectric conversion efficiency in near-infrared region deteriorates due to shortening of absorption wavelength
Solution Approach 1:
The patent applies different materials to different functional requirements within the same light absorption layer. Bromine-based perovskite provides durability and structural stability, while embedded quantum dots provide near-infrared light absorption capability. Each component is optimized for its specific function within the composite structure.
Solution Approach 2:
By combining bromine-based perovskite compounds with quantum dots, the patent achieves both durability from the perovskite matrix and near-infrared photoelectric conversion efficiency from the quantum dots, overcoming the limitations of using either material alone.
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 combination significantly improves the durability and photoelectric conversion efficiency of the photoelectric conversion element, particularly in the near-infrared light region, by suppressing hydrolysis and oxidation reactions, leading to a more stable and efficient solar cell performance.
Implementation Method 1
A photoelectric conversion element that converts light energy into electric energy
Implementation Method 2
it is known that the band gap energy increases (shortening of the absorption wavelength) as the particle size of quantum dots decreases
Implementation Method 3
since the perovskite compound is decomposed by moisture in the atmosphere
Implementation Method 4
since quantum dots are easily surface-oxidized in the atmosphere, the photoelectric conversion efficiency decreases with the lapse of time
Data Source
AI summary
The present invention pertains to a light absorption layer for forming a solar cell and a photoelectric conversion element having excellent durability and photoelectric conversion efficiency in the near infrared region, and a solar cell and a photoelectric conversion element having the light absorption layer. This light absorption layer contains a perovskite compound having a band gap energy of 1.7-4.0 eV, and a quantum dot having a band gap energy equal to or higher than 0.2 eV and equal to or lower than the band gap energy of the perovskite compound.