Method for Producing a Wafer-Based, Rear-Contact Heterojunction Solar Cell and Heterojunction Solar Cell Produced by the Method

Simple SummaryContent extracted from patent full text and abstract with AI.

The patent describes a new method for manufacturing wafer-based, rear-contacted hetero-junction solar cells. In this method, the point or stripe-shaped contacts are first deposited onto the back side of the absorber wafer, after which the functional semiconductor layers are deposited, allowing these layers to conform to and be structured by the underlying contacts. This process eliminates the need for complex and resolution-limiting structuring steps, such as laser drilling, commonly required in previous processes. Selective removal of specific layers from the contact areas prevents short circuits and ensures electrical isolation between different contact systems.

Use CasesContent extracted from patent full text and abstract with AI.

• Manufacturing high-efficiency silicon heterojunction solar cells with rear-side contacts for photovoltaic panels.
• Application in the production of solar modules where reduced front-side shading and higher aesthetics are required (e.g., building-integrated photovoltaics, premium consumer solar products).
• Industrial solar cell fabrication lines seeking to reduce process complexity, cost, and improve scalability.
• Development of custom solar cells with advanced contact architectures for research, aerospace, or specialty electronics.

BenefitsContent extracted from patent full text and abstract with AI.

• Eliminates complex and costly structuring steps (e.g., laser drilling) in solar cell manufacturing, reducing production difficulty and cost.
• Enables implicit, high-resolution patterning of contact structures by depositing contacts first, improving manufacturing precision.
• Improves efficiency by allowing full front-side passivation and eliminating shading losses caused by front contacts.
• Reduces risk of electrical short circuits through selective layer removal at contacts, enhancing reliability and cell performance.
• Facilitates easier module integration and provides better aesthetics, as all contacts are on the cell's rear side.

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

Back contacts require absorber contact systems having punctiform or strip contacts, which extend through the layer design on the absorber wafer. Known manufacturing methods first produce the layer design and subsequently structure the same. Complex and resolution-limiting structuring measures, in particular complex laser-supported boring, are required. According to the invention, first the punctiform or strip contacts (07) are applied in a specified height and distribution onto the absorber wafer (01), whereupon all subsequently applied functional layers surround the same and are thereby implicitly structured. In this way, all resolution-limiting structuring steps are eliminated. In order to prevent short circuits and for contacting purposes, individual functional layers on the punctiform or strip contacts (07) are selectively removed again. For this purpose, the punctiform or strip contacts (07) comprise square edges (08), which during production of the layer design are provided with lesser layer thicknesses compared to horizontal surfaces. They can be removed selectively because during removal layer thicknesses remain on the horizontal surfaces. Hetero solar cells (18) that are produced preferably comprise point contacts (07) in the form of needles (10), or strip contacts in the form of edges.