The Correlation between Dislocations and Vacancy Defects using Positron Annihilation Spectroscopy

An analysis program for positron annihilation lifetime spectrais onlyapplicableto isolated defects,but is of no use inthe presence of defective correlations. Such limitationshavelong causedproblems forpositronresearchers in theirstudies of complicated defective systems. In order to solvethis problem,we aim to take asemiconductor material, for example,to achieve acredible average lifetime of single crystal siliconunder plastic deformation at different temperaturesusing positron lifetimespectroscopy. By establishingreasonable positron trapping modelswith defective correlations and sortingout four lifetime components with multiple parameters, as well as theirrespective intensities,information is obtained on the positron trapping centers, such as the positron trapping rates of defects, the density of the dislocation lines and correlation between the dislocation lines, and the vacancydefects,by fitting with the average lifetime with the aid of Matlab software. These results give strong grounds for the existence ofdislocation-vacancy correlation in plastically deformed silicon, and lay a theoretical foundation for the analysis ofpositron lifetime spectra whenthe positron trapping model involvesdislocation-relateddefects.