Metal-Semiconductor Eutectic Contacts to Reduce Contact Resistance
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Solution Overview
Problem
The existing metal-semiconductor contact structures in solar cells suffer from high contact resistance and irreversible corrosion, which adversely affect the open circuit voltage and photoelectric conversion efficiency.
Innovation Solution
A novel metal-semiconductor contact structure with a conductive eutectic and crystalline conductive crystal is introduced, along with a low-temperature sintering process and laser-induced contact treatment, to optimize the contact performance by reducing resistance and minimizing corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional printing and sintering paste is used to form metal-semiconductor contact, then the contact structure can be fabricated, but the contact resistance between metal material and semiconductor material is large
Solution Approach 1:
The patent changes the thermal processing parameters by introducing a low-temperature sintering process (500-650°C) followed by laser-induced contact treatment, replacing conventional high-temperature sintering. This parameter change enables the formation of conductive eutectic and crystalline structures that reduce contact resistance while avoiding excessive corrosion of the semiconductor surface.
Solution Approach 2:
The patent utilizes phase transitions of the metal material during the low-temperature sintering and laser treatment processes. The metal undergoes phase changes to form conductive eutectic structures and crystalline phases, which significantly improve electrical conductivity and reduce contact resistance at the metal-semiconductor interface.
2Reliability
If conventional high-temperature sintering is used, then contact resistance can be reduced, but irreversible corrosion of the semiconductor layer occurs
Solution Approach 1:
The patent fundamentally changes the temperature parameter by implementing low-temperature sintering (500-650°C) instead of conventional high-temperature sintering. This parameter change reduces the thermal damage to the semiconductor layer while still enabling sufficient contact resistance reduction through the formation of conductive eutectic and crystalline structures.
Solution Approach 2:
The patent replaces the thermal field-based conventional sintering process with a combined low-temperature sintering and laser-induced contact treatment process. The laser treatment provides localized heating and energy input that facilitates conductive structure formation without requiring prolonged high-temperature exposure, thereby minimizing corrosion.
3Ease of manufacture
If conventional sintering process is used, then metal particles can be spheroidized, but carrier transport capacity is insufficient
Solution Approach 1:
The patent utilizes phase transitions during low-temperature sintering and laser treatment to transform metal particles into conductive eutectic structures and crystalline phases. These phase-changed structures provide superior electrical conductivity and carrier transport capacity compared to conventional spheroidized particles.
Solution Approach 2:
The patent creates composite conductive structures at the metal-semiconductor contact interface, combining conductive eutectic phases and crystalline metal structures. These composite structures provide multiple pathways for carrier transport, significantly enhancing the carrier transport capacity while maintaining manufacturability.
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 proposed structure enhances carrier transport and reduces contact resistance, leading to improved open circuit voltage and photoelectric conversion efficiency in solar cells.
Implementation Method 1
the conductive eutectic includes a eutectic formed by the metal element and the semiconductor element
Implementation Method 2
the conductive crystal includes a crystal formed by crystallization of the metal element
Implementation Method 3
The glass frit is in contact with the semiconductor layer and ablates a portion of a passivation layer on the semiconductor layer
Implementation Method 4
applying a reverse bias voltage to the electrode precursor and simultaneously performing laser-induced contact treatment to form the metal electrode
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present application relates to the field of solar cells, and in particular to a metal-semiconductor contact structure and a preparation method thereof, a solar cell and a photovoltaic module. The metal-semiconductor contact structure includes a metal electrode and a semiconductor layer in contact with each other. The metal electrode has a metal element, and the semiconductor layer has a semiconductor element and a doping element for doping the semiconductor layer. A contact interface between the metal electrode and the semiconductor layer has a hole and a conductive structure. The conductive structure includes a conductive eutectic adjacent to the semiconductor layer, and a conductive crystal extending from the conductive eutectic into the hole. The conductive eutectic includes a eutectic formed by the metal element and the semiconductor element, and the conductive crystal includes a crystal formed by crystallization of the metal element. The metal-semiconductor contact structure can improve a contact performance of the metal-semiconductor contact structure, and further promote the improvement of performance indexes such as open circuit voltage and photoelectric conversion efficiency of a solar cell.