Automated Defect Analysis in Solar Cells Using EBIC

Abstract Electron Beam Induced Current (EBIC) characterization is unique in its ability to provide quantitative high-resolution imaging of electrical defects in solar cells. In particular, EBIC makes it possible to image electrical activity of single dislocations in a Dual-Beam Focused Ion Beam (FIB) Scanning Electron Microscope (SEM), to cut and lift out a micro-specimen containing a particular dislocation, and then transfer it for further structural or chemical analysis. As typical solar cell material presents a complex array of defects, it is important to observe statistical variations within a sample and select key sites for analysis. This paper describes a method for automated defect identification and characterization, and shows an application to multi-crystalline silicon (mc-Si) solar cell wafers selected from different heights along the manufactured ingot. Information presented here includes the experimental setup for data acquisition, as well as the basic algorithms used for identification and extraction of dislocation contrast.