Efficient methods for detection of SiC and Si₃N₄ precipitates and filaments in multi‐crystalline silicon wafers and solar cells

Abstract

Two easy and efficient methods are demonstrated to detect SiC and Si3N4 filaments and precipitates in multi-crystalline silicon (mc-Si) wafers and solar cells by Optical Light (OLM) Microscopy and Scanning Electron Microscopy (SEM). In the case of OLM the image is created in the dark field mode which clearly visualizes the grain boundaries decorated by filaments in acidic etched silicon solar cells. In the case of SEM the image is created by a combination of Secondary Electrons (SE) imaging and Back Scattered Electrons (BSE) imaging. By using this method a clear discrimination of precipitates with different chemical compositions is possible. Note that both methods make it possible to investigate and analyze relatively large sample areas in a comparatively short period of time

Erlangen—An Important Center of Crystal Growth and Epitaxy: Major Scientific Results and Technological Solutions of the Last Four Decades

“…A fundamental scientific understanding on the formation of C and N related precipitates was achieved by profound experimental analysis and numerical modeling of the convective heat and mass transport processes in the Ph.D. work of Christian Reimann. A series of scientific papers was published on this topic . Based on these findings technical solutions, which were partially patented, how to avoid the harmful crystal defects were proposed.…”