Dome-Array Photovoltaic Structure With Metal-Less Back Reflector
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Solution Overview
Problem
Existing solar cell architectures rely on expensive metals like silver for reflector/electrode structures, which are costly and time-consuming to process, and often require texturing that complicates manufacturing, while also suffering from plasmonic losses and performance degradation due to sharp features.
Innovation Solution
A photovoltaic device with a periodic array of dome-like protrusions at the front surface and a metal-less reflector/electrode back contact structure using transparent conductive materials, which refracts light to enhance momentum parallel to the back contact and eliminates the need for metal layers and texturing, fabricated without hard mask deposition and etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal layers (silver) are used for reflector/electrode structures, then optical reflectivity and electrical conductivity are improved, but manufacturing cost and processing time increase
Solution Approach 1:
The patent removes the metal layer from the back reflector/electrode structure, extracting the expensive and complex component while retaining the essential optical function through a transparent conductive material (TCO) layer combined with a dielectric layer. This extraction eliminates the need for vacuum deposition processes and reduces material costs while maintaining reflectivity through alternative optical design.
Solution Approach 2:
The patent replaces expensive metal layers with cheaper transparent conductive materials such as ITO (indium tin oxide), IZO (indium zinc oxide), or GZO (gallium zinc oxide). These TCO materials are less expensive than silver and can be deposited using simpler, less time-consuming processes while providing sufficient electrical conductivity and optical transparency.
2Reliability
If metal layers are used for reflector/electrode structures, then electrical conductivity is improved, but processing time and complexity increase
Solution Approach 1:
The patent removes the metal layer from the back reflector/electrode structure, extracting the expensive and complex component while retaining the essential optical function through a transparent conductive material (TCO) layer combined with a dielectric layer. This extraction eliminates the need for vacuum deposition processes and reduces material costs while maintaining reflectivity through alternative optical design.
Solution Approach 2:
The patent replaces the metal-based electrical conduction system with a transparent conductive material system that achieves electrical conductivity through different physical mechanisms (carrier concentration control in semiconducting materials) rather than through metallic conduction, enabling simpler deposition processes.
3Use of energy by moving object
If texturing is used for light management, then light absorption is improved, but manufacturing complexity increases
Solution Approach 1:
Instead of creating complex surface textures to enhance light absorption, the patent inverts the approach by using a flat surface with a transparent conductive material layer that utilizes optical interference and reflection from the dielectric layer to achieve light management. This inversion simplifies manufacturing while maintaining optical performance.
Solution Approach 2:
The patent changes the optical parameters by introducing a dielectric layer with specific refractive index and thickness to control light reflection and absorption. By adjusting the dielectric layer parameters (thickness, material composition) rather than surface geometry, the system achieves light management with simpler manufacturing processes.
4Reliability
If metal layers are used for reflector structures, then optical performance is improved, but plasmonic losses occur
Solution Approach 1:
The patent removes the metal layer from the back reflector/electrode structure, extracting the expensive and complex component while retaining the essential optical function through a transparent conductive material (TCO) layer combined with a dielectric layer. This extraction eliminates the need for vacuum deposition processes and reduces material costs while maintaining reflectivity through alternative optical design.
Solution Approach 2:
The patent converts the harmful plasmonic losses associated with metal layers into beneficial optical interference effects by using a transparent conductive material with a dielectric layer. The TCO layer, combined with the dielectric layer, creates constructive interference for light reflection while avoiding the energy-dissipating plasmonic resonances that occur in metal structures.
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
This design improves light utilization and reduces manufacturing costs by avoiding expensive metals and simplifying processing, while maintaining or exceeding the performance of traditional structures with metal-based reflectors, and enhances short circuit current density and device efficiency.
Implementation Method 1
The beneficial interaction between an appropriately designed top protrusion array and these reflector/electrode back contacts (R/EBCs) serves (1) to refract the incoming light in a manner to thereby provide photons with an advantageous larger momentum component parallel to the plane of the back (R/EBC) contact
Implementation Method 2
Each reflector/back electrode form operates as a back light reflector and counter electrode to the periodic array of dome or dome-like structures
Data Source
AI summary
A photovoltaic or light detecting device is provided that includes a periodic array of dome or dome-like protrusions at the light impingement surface and three forms of reflector/back electrode at the device back. The beneficial interaction between an appropriately designed top protrusion array and these reflector/electrode back contacts (R/EBCs) serve (1) to refract the incoming light thereby providing photons with an advantageous larger momentum component parallel to the plane of the back (R/EBC) contact and (2) to provide optical impedance matching for the short wavelength incoming light. The reflector/back electrode operates as a back light reflector and counter electrode to the periodic array of dome or dome-like structures. A substrate supports the reflector/back electrode.