Violet photoluminescence from Ge +-implanted Si-based nanoscale SiO 2 islands array

Abstract

Ge ions were implanted into a SiO 2 nanoscale islands array at an energy of 200 keV with a dose of 1×10 17 cm −2. Violet photoluminescence (PL) bands peaked at 370, 396, and 415 nm from Ge + implanted SiO 2 nanoscale islands array were observed, and the violet PL spectra reached a maximum after annealing in N 2 ambient at 700°C. From photoluminescence excitation (PLE) spectra of samples we found an excitation band at around 270 nm besides a widely known excitation band at around 240 nm. We tentatively conclude that PLE band at around 270 nm and luminescence at 370 and 415 nm may be caused by Ge-associated neutral oxygen vacancy (denoted as Ge Si and GeGe), while the 396 nm PL band arise from GeO color centers.