Diffractive Optical Element Design for Solar Cell Efficiency
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Solution Overview
Problem
Current diffractive optical elements for color-separating and focusing have low diffraction efficiency, limiting their application in solar cells and requiring costly and complex manufacturing processes.
Innovation Solution
A design method for diffractive optical elements that calculates modulation thicknesses at sampling points using the Yang-Gu algorithm, allowing for a range of equivalent modulation phases and thicknesses, enabling improved flexibility and fabrication using photolithography for mass production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional design methods are used for diffractive optical elements, then color-separating and focusing functions can be achieved, but diffraction efficiency is limited to 10%-20%
Solution Approach 1:
The patent applies parameter changes by optimizing the modulation thickness of the diffractive optical element. Specifically, it determines modulation thicknesses at different sampling points on the DOE surface to maximize diffraction efficiency. The method calculates and adjusts the thickness parameter at each sampling point to achieve constructive interference for the desired diffraction order, thereby improving energy utilization from 10%-20% to significantly higher levels while maintaining color-separation and focusing functions.
2Loss of energy
If high diffraction efficiency is achieved through optimized modulation thickness, then energy utilization improves, but manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the diffractive optical element surface into multiple sampling points where modulation thickness is independently optimized. This allows the complex manufacturing process to be broken down into discrete, manageable steps - calculating thickness at each sampling point separately and then fabricating the overall structure. The segmentation approach makes the complex optimization problem solvable and the manufacturing process more controllable.
Solution Approach 2:
The patent changes the modulation thickness parameter at different sampling points to achieve high diffraction efficiency. By systematically varying this critical parameter across the DOE surface based on calculated optimal values, the method achieves superior optical performance while providing clear fabrication guidelines that balance manufacturing feasibility with performance requirements.
3Loss of energy
If modulation thickness is optimized at each sampling point, then diffraction efficiency exceeds 79%, but design and calculation complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-calculating the optimal modulation thickness at each sampling point before fabrication. The design method performs comprehensive calculations in advance to determine the exact thickness required at each location to achieve maximum diffraction efficiency. This preliminary design phase creates a complete fabrication blueprint, simplifying the actual manufacturing process and reducing on-the-spot decision complexity.
Solution Approach 2:
The patent uses copying by creating a detailed design model that specifies modulation thickness at each sampling point. This digital design template can be replicated and used for manufacturing multiple identical high-efficiency DOEs. Once the optimal thickness distribution is calculated for one DOE, the same design can be copied and manufactured repeatedly, reducing design complexity for subsequent productions.
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 method significantly enhances diffraction efficiency to over 79%, reducing manufacturing costs and enabling practical application in solar cells by optimizing modulation thickness selection.
Implementation Method 1
A diffractive optical element (DOE) is an optical element performing optical functions of such as focusing, color-separation (wavelength demultiplexing), refraction, reflection and imaging based on the optical diffraction principle
Implementation Method 2
when sunlight irradiates photovoltaic materials in the solar cell, e.g., semiconductor materials, the semiconductor materials convert light energy into electrical energy because of a photovoltaic effect after absorbing the sunlight irradiation
Data Source
AI summary
Disclosed are a diffractive optical element, a design method thereof and the application thereof in a solar cell. The design method for a design modulation thickness of a sampling point of the diffractive optical element comprises: calculating the modulation thickness of the current sampling point for each wavelength component; obtaining a series of alternative modulation thicknesses which are mutually equivalent for each modulation thickness, wherein a difference between the corresponding modulation phases is an integral multiple of 2π; and selecting one modulation thickness from the alternative modulation thicknesses of each wavelength to determine the design modulation thickness of the current sampling point. In an embodiment, the design method introduces a thickness optimization algorithm into a Yang-Gu algorithm. The design method breaks through limitations to the modulation thicknesses/modulation phases in the prior art and increases the diffraction efficiency, and the obtained diffractive optical element facilitates mass production by a modern photolithographic technique, which greatly reduces the cost. The diffractive optical element may also be applied to the solar cell, which provides an efficient and low-cost way for solar energy utilization.