Hydrogen Passivation for Cheaper Silicon PV Devices
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Solution Overview
Problem
Current methods for manufacturing high-efficiency photovoltaic devices rely on high-quality silicon materials and high-temperature processes, which are costly and limit the use of cheaper silicon, and struggle to effectively passivate electrically active defects in silicon photovoltaic devices.
Innovation Solution
The method involves performing hydrogen passivation processes at temperatures above and below 500°C to generate excess minority carriers, allowing for the passivation of electrically active defects in the bulk region of silicon materials, enabling the use of cheaper silicon to manufacture high-efficiency photovoltaic devices without requiring high-quality silicon wafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional high-temperature firing processes (above 800°C) are used to form metal-silicon contacts, then electrical contact quality is improved, but aluminium-silicon alloyed p+ regions form which can introduce recombination centers and reduce device efficiency
Solution Approach 1:
The patent changes the temperature parameter from conventional high-temperature firing (above 800°C) to low-temperature processing (below 200°C), and alters the chemical composition by using zinc oxide instead of aluminium paste, thereby avoiding the formation of harmful aluminium-silicon alloyed regions while maintaining good electrical contact quality
Solution Approach 2:
The patent uses zinc oxide, a cheaper and more environmentally friendly material替代 aluminium paste, which achieves the same electrical contact function without creating persistent harmful alloyed regions in the silicon substrate
2Ease of manufacture
If typical processing sequences for hetero-interface devices are used, then device fabrication is simplified, but electrical quality of silicon cannot be improved due to absence of high-temperature steps
Solution Approach 1:
The patent performs preliminary low-temperature hydrogen passivation (below 200°C) before subsequent high-temperature processing steps, which prepares the silicon bulk for improved electrical quality without requiring complex high-temperature processing sequences, thereby maintaining ease of manufacture while improving electrical quality
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 approach enhances the electrical quality of silicon photovoltaic devices, improves charge carrier lifetimes, and allows for the production of high-efficiency devices using less expensive silicon materials, while maintaining the performance of high-quality solar structures.
Implementation Method 1
performing a first hydrogen passivation process at a temperature above 500° C. in a manner such that excess minority carriers are generated in the silicon material
Implementation Method 2
in a manner such that excess minority carriers are generated in the silicon material
Implementation Method 3
forming a first layer of intrinsic amorphous silicon onto a first surface of the substrate
Implementation Method 4
forming a region of silicon material with a second polarity into the doped silicon material
Implementation Method 5
forming metallic contacts to extract charge carriers from the silicon material
Data Source
AI summary
The present disclosure provides methodologies for manufacturing high efficiency silicon photovoltaic devices using hydrogen passivation to improve performance. The processing techniques disclosed use tailored thermal processes, sometimes coupled with exposure to radiation to enable the use of cheaper silicon material to manufacture high efficiency photovoltaic devices.