Fine Structure of Dislocation Related PL Bands D1 and D2 in Silicon
The samples of p- and n-doped Fz Si were deformed in 3-point bending mode in the temperature range 800-950°C. The fine structure of dislocation related luminescence in the region of D1 and D2 bands was most pronounced at lowest rate of deformation. The temperature variation of intensity of individual lines did not reveal any thermalization effects. It implies that centers responsible for different individual lines are situated in diverse places. The most narrow lines with maximum positions of 802 meV and 807 meV (D1 band) and 869 meV and 873 meV (D2 band) are rapidly quenched with increase in temperature, while the broader background lines survive at higher temperature. The new line with maximum position at about 882 meV appears in the D2 band with enhanced carbon doping. It was found that at higher P-doping the low energy fine structure lines 802 meV and 869 meV are absent. Besides, the Fz samples with different P doping level from 6×1014 cm-3 to 1.2×1016 cm-3 demonstrate quite a different temperature variation of broad background lines. At lowest level of P-doping they move to low energy side at temperature above 30K, while at P-doping above 1015 cm-3 these lines move to higher energy in the same temperature range. A possible explanation of this observation can be related to distribution of electrons in the cband. It implies that the corresponding electronic transitions occur between the edge of conduction band and deep states.
B. Pichaud, A. Claverie, D. Alquier, H. Richter and M. Kittler
E.A. Steinman et al., "Fine Structure of Dislocation Related PL Bands D1 and D2 in Silicon", Solid State Phenomena, Vols. 108-109, pp. 767-772, 2005