Temperature-dependent photoluminescence spectroscopy of silicon nanowires grown via silver assisted chemical etching
Abstract
We investigate the temperature-dependence of the photoluminescence (PL) bands in silicon nanowires (SiNWs) grown via silver-assisted chemical etching. SINWs were grown from B-doped p-type (100) silicon substrates via silver-assisted chemical etching. Scanning electron micrographs confirmed the presence of SINWs approximately 3 microns in length. Temperature-dependent PL results revealed the presence of two peaks at E1 ≈ 1.88 eV and E2 ≈ 2.18 eV. These peaks do not obey the temperature dependence of semiconductors as suggested by the Varshni equation. Furthermore, anomalous thermal quenching was observed for several temperature values. In summary, we attribute the origin of these photoluminescence bands to defect sites in the Si/SiO2 interface rather than spatial confinement effects.