Switchable absorber element and photovoltaic cell
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Solution Overview
Problem
Existing shading systems in high-rise buildings with large window facades are maintenance-intensive and inefficient, as they either block light without harnessing its energy or combine mechanical shading with solar cells in a way that wastes dynamically blocked light energy.
Innovation Solution
A switchable absorber element with a thin photoelectrically active absorber layer between switchable reflection layers, allowing for reversible light transmission and absorption, integrated into a photovoltaic cell with charge carrier-selective electrodes, to maximize energy yield and shading effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If mechanical shading systems are used, then shading effect is achieved, but maintenance intensity increases and reliability decreases
Solution Approach 1:
The patent replaces mechanical shading systems with an electro-optical system. The absorber element can be switched between transparent and absorbing states through electrical control, eliminating moving parts and mechanical components. This substitution resolves the contradiction by maintaining shading effectiveness while dramatically improving reliability through a maintenance-free solid-state system.
2Use of energy by moving object
If solar cells are combined with mechanical shading, then energy generation is achieved, but dynamically blocked light energy is wasted
Solution Approach 1:
The patent converts the previously wasted blocked light energy into useful electrical energy. The absorber element, when in absorbing state, captures light that would otherwise be blocked and converts it to electricity through the photovoltaic effect. This resolves the contradiction by transforming energy loss into energy gain, simultaneously achieving shading and power generation.
3Manufacturing precision
If absorber layer thickness is reduced, then manufacturing precision improves, but absorption capacity decreases
Solution Approach 1:
The patent compensates for reduced absorber layer thickness by introducing optical resonance through front and rear reflection layers. This creates multiple light passes through the thin absorber layer, effectively increasing the optical path length without increasing physical thickness. The resonance effect multiplies the absorption capacity, resolving the contradiction between thin-layer manufacturing precision and absorption performance.
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 solution enables efficient charge carrier regeneration and high electrical energy production while providing a high shading effect, with minimal light transmission during absorption and maximum transmission during shading, optimizing energy use and reducing maintenance needs.
Implementation Method 1
solar cells have an absorber element, in which free charge carriers can be created by the supply of energy in the form of electromagnetic radiation
Implementation Method 2
Resonances or stationary waves or multiple reflections, respectively, are created between the reflecting layers under certain conditions
Implementation Method 3
at least one of the reflection layers has a switchable reflectivity
Data Source
AI summary
The invention relates to a switchable absorber element and a photovoltaic cell based thereon. A switchable absorber element according to the invention has an absorber layer. The absorber element furthermore has at least one front side reflection layer and at least one rear side reflection layer, wherein the absorber layer is arranged between front side reflection layer and rear side reflection layer, wherein the optical path length between front side reflection layer and rear side reflection layer is less than 400 nm at least for light impinging perpendicularly onto the cell. The absorber element according to the invention is characterized in that at least one of the reflection layers has a switchable reflectivity.