Quasi Mono Crystalline solar cells
Quasi mono crystalline solar cells/ quasi Mono is a cell technology that offers the advantage of a high efficiency cell in the square shape of a poly cell, with a price expected to become similar to a standard mono solar cell.
Currently Quasi Mono cell technology reached the point that it can be used for production, even though some manufacturers seem to have trouble to produce quasi mono solar cells on large scale.
Cell efficiencies of over 18% using quasi-mono wafers have been claimed by several wafer manufacturers, including Gintech, JA Solar and Renesola.
Quasi Mono technology allows casting of the monocrystalline ingot in the DDS furnace by placing a mono seed at the bottom of the crucible.
Technology was originally developed by Ja Solar in cooperation with JingGong Science and technology.
Manufacturing Quasi Mono cells
What remains the same during manufacturing?
The original wafers are still the wafers from standard DS furnaces, and the cell manufacturing process is 90% the same. The pv module manufacturing process remains identical.
What has been improved during manufacturing?
As you can see from the photos, the wafer quality has been improved by reducing the number of grains, which reduces the chance of surface recombination / defects. Further the way the solar cell is textured has been changed to alkaline texturing.
Advantages – Why would a Quasi Mono solar cell be better than a standard poly or mono cell?
Quasi Mono solar cells have up to 4% higher conversion efficiency than traditional polycrystalline solar cells, while the manufacturing costs remain about the same as poly crystalline cells. To benefit from this price, Quasi Mono cells need to be produced on large scale.
This new manufacturing process allows multi-crystalline cell manufacturers to increase the efficiency of its cells for a small investment in manufacturing equipment. As the cell manufacturing equipment can be easily upgraded, it is likely more manufacturers will start producing quasi mono cells.
Besides gains in efficiency and cost reduction, due to the higher degree of purity in the solar cell the number of defects is reduced.
Better low light performance
Finally the pv module’s low light performance is improved due to the better solar cell surface texturing.
Quasi Mono Solar Cells – Applications
The higher efficiency of cells means that a standard 60 or 72 cells pv module can produce 255W or 300W, which is excellent for roofs with limited surface available.
Suppliers in China and Taiwan that offer Quasi Mono cells
NOTE: it seems that several manufacturers of Quasi Mono Solar Cells had problems in the manufacturing and have ceased production.
Aide Solar has launched a range of quasi-mono modules, the highest power is 320w and the quasi-mono modules’ efficiency reaches up to 16.3%.
The company claims the surface color is better than standard poly modules and the efficiency is 4% higher than polycrystalline pv modules.
ReneSola developed their Quasi-mono wafer-Virtus®, which improves the average conversion efficiency of conventional multicrystalline wafers from 16.5% to more than 18.2%.
JA Solar is producing its Maple quasi-mono solar cells in limited volume and the company has reached an average conversion efficiency of 18%, which is a new record for JA Solar.
Gintech Energy produces its so called Hybrid cells that reach efficiencies up to 18.2%. Download datasheet here.