Two canals of recombination on real silicon surfaces

Two recombination channels are found on a real Si surface, yielding comparable contributions to the rate of surface recombination. These channels are associated with two types of recombination centers, the first of which corresponds with the discrete level located near the middle of the forbidden Si zone, and the second of which with levels continuously distributed throughout the forbidden zone. The first type of recombination center appears upon localization of water molecules near definite defects at the Si-oxide interface, and the second type of center, upon the removal of the SiOF$_{2}$ group oxide in the process of different thermal and chemical treatments. It is shown that the first type of recombination center is twice as effective in recombination than the first type.