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 have 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 two 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 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 is explained by means of the heavy atom effect.