Posted 5.19.2016 in Reviews by Christopher
In 2010, Mitsubishi produced a polycrystalline solar cell with a world-record setting 19.3% efficiency. Mitsubishi has taken what they’ve learned from developing that record-setting technology and applied it to their residential solar panels.
They developed a technique of soldering the emitter that doesn’t require excessive doping. In solar cell manufacturing, the level of doping concentration is a trade-off between having enough conductivity to transfer the generated electricity without allowing recombination of the generated charge: too much dope and you lose electrical charge, too little dope and the charge generated is lost due to too much resistance. Mitsubishi developed a selective emitter in which only the area in contact with the electrodes is doped. This improvement resulted in an increase in cell output of approximately 5%. The company has also developed half-cut cells. By reducing the area of each cell and connecting them in a parallel formation, the amount of electrical current carried by each busbar is reduced by half. This innovation increases module efficiency by about 2.5%. Looking for more ways to increase the light-receiving area of their cells, they also developed fine-grid electrodes. By using more busbars because of the half-cut cell design, Mitsubishi busbars disperse stress resulting in less potential for cracking. While optimizing the busbars, they also increased the distance between the busbar and module frame so power isn't reduced when dust or snow builds up on the module corners.