Strong photoluminescence of Sn-implanted thermally grown SiO2 layers

The photoluminescence (PL) and PL excitation (PLE) properties of Sn-implanted SiO2 layers thermally grown on crystalline Si has been investigated and compared with those from Ge- and Si-implanted SiO2 layers. In detail, the violet PL of Sn-implanted SiO2 layers is approximately 2 and 20 times higher than those of Ge- and Si-implanted SiO2 layers, respectively. Based on PL, PLE and decay time measurements the violet PL is interpreted as due to a triplet-singlet transition of the neutral oxygen vacancy (NOV) typical for Si-rich SiO2 and similar Ge- and Sn-related defects in Ge- and Sn-implanted SiO2 films. The enhancement of the blue-violet PL within the isoelectronic row of Si, Ge and Sn will be explained by means of the heavy atom effect.