Buried Contact Solar Cells

Source: MDPI

The Buried Contact Solar Cell Technology

The buried contact solar cell is a high-efficiency commercial solar cell technology that utilizes a plated metal contact inside a laser-formed groove. This innovative technology overcomes many limitations associated with traditional screen-printed contacts, allowing for a significant performance improvement of up to 25% compared to commercial screen-printed solar cells.

Key Features of Buried Contact Solar Cells

One of the key features of buried contact solar cells is the placement of metal contacts inside laser-formed grooves within the silicon solar cell. This design enables a high metal aspect ratio, allowing for a large volume of metal in the contact finger without the need for a wide strip of metal on the top surface. As a result, a large number of closely spaced metal fingers can be incorporated while maintaining high transparency.

Compared to screen-printed solar cells, buried contact structures experience significantly lower shading losses, leading to enhanced light absorption and higher short-circuit currents.

Advantages of Buried Contact Technology

Buried contact technology offers low parasitic resistance losses due to its high metal aspect ratio, fine finger spacing, and the use of plated metal contacts. These factors contribute to reduced emitter resistance, low metal grid resistance, and lower contact resistance, resulting in high fill factors for large area solar cells.

Moreover, the metalization scheme of buried contact solar cells improves the cell’s emitter, allowing for optimized doping levels that enhance open-circuit voltages and short-circuit currents. The inclusion of a self-aligned, selective emitter further reduces contact recombination and boosts open-circuit voltages.

Efficiency and Cost Benefits

The efficiency advantages of buried contact technology translate into significant cost and performance benefits. While the cost per watt of buried contact solar cells is comparable to screen-printed cells, the higher efficiency of the former results in lower-cost electricity generation when considering area-related and fixed costs in a PV system.

Additionally, buried contact technology is suitable for use in concentrator systems, further expanding its applicability in solar energy generation.

The production sequence for laser grooved buried contact solar cells involves advanced manufacturing processes to achieve the desired cell structure and performance.

Source: Journals