Effect of Rapid Thermal Annealing on the Photoluminescence from Si Nanocrystal Decorated Si Nanowires Array Grown by a Metal Assisted Chemical Etching Method

Abstract

In this report, the micron-long Si nanowires (NWs) array is grown by a metal assisted chemical etching (MACE) process using Ag as the noble metal catalyst in HF/H2O2 solution. These Si NWs are decorated with arbitrary shaped ultrasmall Si nanocrystals (NCs) due to the side wall etching of the Si NWs. The MACE grown samples exhibit strong PL emission in the visible region and quantum confinement (QC) effect of photon in the Si NCs is believed to be the dominant mechanism behind PL. We have investigated the influence of rapid thermal annealing with different annealing environments on the optical properties (such as PL, Raman and reflectivity) of the Si NCs decorated Si NWs samples to gain better insight into the QC effect. The effect of laser excitation power on the PL properties of the as-grown Si NCs/NWs sample are also inspected in this report for further confirmation of QC effect behind the PL emission profile.