Photovoltaic properties of silicon nanocrystals in silicon nitride prepared by ammonia sputtering

Abstract

In this work, we present an investigation of the photovoltaic properties of low-temperature (700°C annealing temperature) prepared P -doped Silicon nanocrystals ( Si   NCs ) in silicon nitride by ammonia sputtering followed by rapid thermal annealing (RTA). We examined how the flow rate of NH3influenced the structural properties of the annealed films by using Raman scattering, grazing incidence X-ray diffraction (GI XRD) and transmission electron microscopy (TEM), it was found that the appropriate flow rate of NH3is 3 sccm. For the sample deposited at the flow rate of 3 sccm, TEM image showed that Si   NCs were formed with a mean size about 3.7 nm and the density of ~ 2.1 × 1012cm-2; X-ray photoelectron spectroscopy (XPS) characterization showed the existence of Si – P bonds, indicating effective P doping; the average absorptance of higher than 65% and a significant amount of photocurrent makes it suitable for photoactive. Moreover, the experimental P -doped Si   NCs : Si3N4/ p - Si heterojunction solar cell has been fabricated, and the device performance was studied. The photovoltaic device fabricated exhibits an open-circuit voltage (VOC) and a short-circuit current density (JSC) of 470 mV and 3.25 mA/cm2, respectively.