Identify one tool that helps with identify a photoactive pro

Identify one tool that helps with identify a photoactive property of a material. Provide the following Name of tool Operating principle of the tool [labeled schematic] What property/properties of a material does the tool aid with identifying Describe the principle of operation Example of a photoactive material that has been characterized using the tool Reference

Solution

ELYMAT (Electrolytical metal analysis tool)

ELYMAT is a measurement technique for mapping the minority carrier diffusion lengths in Si wafers. It is mounted in a double electrochemical cell. The edge of the wafer is contacted by tungsten carbide tips. Both half cells are filled with a HF containing electrolyte. This results in the build-up of Schottky contacts on both sides of the wafer. Platinum wires are immersed in the electrolytes on both sides of the cells used as electrodes. A focused laser beam can be scanned onto the front side of the wafer. The resulting photocurrent can be collected either from front or back side of the wafer, or from both sides simultaneously. Thus the measured photocurrents depend mainly on local diffusion length. Using lasers with different wavelengths provides information on diffusion length and allows one to distinguish between bulk and surface recombinant processes.

Applications: