Effect of deposition direction on the properties of silicon layers fabricated from recycled silicon powder

Abstract

In this research, the recycled silicon (RSi) nanopowder of 50 nm diameter was used to fabricate Silicon Microwires (SiMWs) arrays using the Cold Spraying Technique (CST). In addition, Silicon Thin Films (SiTFs) of 2μm thickness was deposited using the Thermal Evaporation Technique (TET). The fabricated SiMWs arrays with the length of 0.15-0.6μ0m and of width 0.1-0.15μm were arranged as arrays on a glass substrate, after the deposition of the initial silicon sub-layer with a thickness of 50A˚, as templates by thermal evaporation. Annealing in vacuum at 400C° was done for both SiMWs and SiTFs. In the CST process, the certified base angles were 0°, 30°, and 45°. Diagnostic and optical properties tests of these SiMWs and SiTFs were conducted. The results show that the deposited wires are crystalline with a direction of 111, and by increasing the deposition angle, the transmittance reduces and the absorbance increases due to internal reflections among extended SiMWs. The initial annealing of the substrate help in the increasing value of the transmittance when it is compared with the normal thin film, which shows more absorbency, making the fine wire applicable for solar cells and other optical applications. Consequently, the optical transparency of the SiMWs will be adequate to figure out their alignment.