Visible photoluminescence in crystallized amorphous Si:H/SiN<i>x</i>:H multiquantum-well structures

Abstract

Visible photoluminescence has been observed in crystallized a-Si:H/a-SiNx:H multiquantum-well structures at room temperature. The MQW heterostructures consisting of 72 layers were formed by computer controlled plasma-enhanced chemical-vapor deposition method and then crystallized by Ar+ laser annealing technique. The crystallinity and average grain size of the silicon microcrystals were determined by means of Raman and x-ray diffraction spectroscopy. The crystallized samples with well-layer thickness Ls=40 Å showed an intense photoluminescence which is peaked at 2.1 eV with a full width at half-maximum of 0.25 eV. This is consistent with calculations based on the quantum confinement model.