Investigating the Influence of Interface and Vacancy Defects on the Growth of Silicon Quantum Dots in SiO2
Abstract
The effects of interface and vacancy defects on silicon quantum dot (Si-QD) growth are investigated using measurements of Time Resolved Photoluminescence (TRPL), Photoluminescence (PL) Spectroscopy and Electron Paramagnetic Resonance (EPR). Thermally grown SiO2 thin films (280nm) were irradiated with high energy (400keV – 1MeV) silicon ions in order to introduce defects into the Si-QD growth layer of SiO2. A noticeable increase in PL emission intensity is seen with the highest energy pre-implanted sample over a single implant sample. TRPL results show increased radiative lifetimes for the lower energy (400keV) pre-implant while little or no difference is seen in TRPL results between the single implant and the higher energy implanted samples. The origin of increased PL emission intensity and a trend towards shorter radiative lifetimes with increased implant energy in TRPL measurements are believed to be due to defect-mediated Si-QD growth in high energy pre-implanted samples.