MICRO-SCALE CHARACTERIZATION OF PERC UNDER THE MANUFACTURING PROCESS BY PHOTO-LUMINESCENCE

Abstract

The passivated emitter and rear cells (PERC) have micro-scale structure on rear side. The micro photo luminescence (PL) is suitable to analyze PERC in a non-destructive. In the case of the objective lens (x5) with microscope and 1 Mega pixel camera, calculated pixel resolution is 2.6μm. Micro-PL results of the passivation layer after Laser contact hole opening (LCO) process shows that passivation region quality is affected up to about 400μm away from the border of the laser contact opening. And micro-PL shows that the PL intensity at local back surface field (BSF) region correlates well with the thickness of BSF layer measured from the cross section of solar cell.