Integrated Solar Cell Substrate Bypass Diode
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Solution Overview
Problem
Existing solar cell technologies face challenges with shadowing effects, which lead to reverse biasing and potential damage, and current bypass diode solutions are cumbersome, costly, and inefficient, particularly in space-related applications where weight and mass are critical.
Innovation Solution
A solar cell assembly with a combined silicon handle substrate and bypass diode, where the substrate functions as a p-n junction for reverse bias protection, reducing mass and cost, and simplifying assembly by integrating the bypass diode into the cell structure, using a silicon substrate to replace germanium for reduced weight and increased robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a separate germanium handle substrate is used to support thin solar cells, then mechanical support is improved, but weight and cost increase
Solution Approach 1:
The patent combines the handle substrate and bypass diode into a single integrated component. The silicon substrate serves dual functions: providing mechanical support for the thin solar cell and functioning as the bypass diode through its p-n junction structure. This eliminates the need for a separate germanium handle substrate, reducing weight while maintaining mechanical support capabilities.
Solution Approach 2:
The patent changes the material parameter from germanium to silicon for the handle substrate. Silicon has lower density and cost compared to germanium, while still providing adequate mechanical support. The substrate is doped to create a p-n junction that provides bypass diode functionality, transforming the substrate from a passive support structure to an active protective component.
2Reliability
If a separate bypass diode is mounted on the solar cell, then reverse bias protection is improved, but device complexity and assembly difficulty increase
Solution Approach 1:
The patent merges the bypass diode function directly into the handle substrate through doping to create a p-n junction. This integrated structure eliminates the need for separate bypass diode components and their associated mounting, wiring, and connection processes, significantly reducing device complexity and assembly difficulty while maintaining reverse bias protection.
Solution Approach 2:
The handle substrate provides its own bypass diode functionality through its p-n junction structure, eliminating the need for external protective components. The substrate serves itself by providing both mechanical support and electrical protection, reducing the overall system complexity.
3Reliability
If discrete silicon bypass diodes are used, then reverse bias protection is improved, but mass and cost increase
Solution Approach 1:
The patent combines the bypass diode functionality into the handle substrate itself, eliminating the need for separate discrete silicon bypass diodes. The p-n junction formed by doping the substrate provides the same protective function while reducing total mass, as the protective function is integrated into the existing support structure rather than added as a separate component.
4Reliability
If bypass diode is affixed to a corner of the solar cell, then protection is improved, but automated handling becomes difficult
Solution Approach 1:
By integrating the bypass diode into the handle substrate that bonds to the entire back surface of the solar cell, the protection is distributed across the full cell area rather than being localized to a corner. This integration maintains protection effectiveness while providing uniform bonding surfaces that facilitate automated handling and assembly processes.
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 solution provides enhanced protection against reverse bias, reduced mass and cost, improved handling, and simplified assembly, enabling efficient energy conversion and reduced degradation, suitable for high-specific-power applications like satellites and aircraft.
Implementation Method 1
The substrate has a p-n junction providing reverse bias protection, and the substrate functions as a bypass diode
Implementation Method 2
Solar cells or photovoltaic cells are devices designed to convert available light into electrical energy
Data Source
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AI summary
A solar cell assembly and method are disclosed. The solar cell assembly comprises a substrate having a front surface and a back surface, wherein the substrate has a p-n junction providing reverse bias protection, and wherein the substrate functions as a bypass diode. The solar cell assembly further comprises a multijunction solar cell having a plurality of solar cell layers, wherein the multijunction solar cell has a first surface and a second surface, the first surface being attached to the front surface of the substrate. The solar cell assembly further comprises an electrical connector element positioned adjacent the front surface of the substrate and the first surface of the multijunction solar cell, a first contact coupled to the back surface of the substrate, and at least one second contact coupled to a portion of the second surface of the multijunction solar cell.