Effect of compressive and stretching strains on the dislocation luminescence spectrum in silicon

Photoluminescence has been studied in silicon deformed by four-point bending at temperature of 600$^\circ$C. So-called dislocation-related luminescence lines D1, D2, D3 and D4 are observed from both the sides of the deformed samples. It is found that in the samples with the induced dislocation density $\sim$10$^7$ cm$^{-2}$, a luminescence intensity of the D3 and D4 lines is the same on both the sample sides, and the intensity of the D1 and D2 lines from the tensile side is higher than that from the compressive side. Behavior of the intensity of the D1 and D2 lines is well correlated with a quantity of dislocation trails. Possible reasons of observed effect are discussed.