Effect of annealing temperature on dark current density of silicon nanocrystals embedded in a nitride matrix for photovoltaic application

The purpose of using high density nano-crystalline silicon embedded in insulator matrices is the energy confinement of Si based quantum dot nanostructures. This approach aims to engineer wide band gap Si materials to be used as upper cell elements in Si based tandem cells in order to increased efficiency and low cost thin film processes. One of the main challenges is to obtain sufficient carrier mobility and hence a reasonably conductivity for photovoltaic application. The results of current density as a function of thermal annealing show the evolution of SiQD formation in Si₃N₄ matrix. As deposited film fabricated by using dual-mode PECVD has composition of ordered Si rich nitride (Si_3+xN₄) arrays.