Fabrication Of Silicon Nanoparticles Research Articles

Application of silicon nanoparticles extracted from the Padma river sand of Bangladesh as dopant in metal oxide semiconducting thin films

Fabrication of silicon nanoparticles (Si-NPs) from the Padma river sand of Bangladesh by a low-temperature, low-cost, and zero-CO2 emitting process and its application as a dopant in CuO and ZnO have been presented in this article with a motivation to see the influence of locally fabricated Si-NPs on the optoelectronic properties of CuO and ZnO thin films. The sand (SiO2) was reduced using a modified aluminothermic reaction, and leaching with hydrochloric acid (HCL) was used to purify the reaction product to extract > 98% pure Si. After cleaning and drying, the obtained Si powder was ultrasonicated for crushing them into tiny particles of 60–180 nm. The ultrasonicated silicon was further treated with a solution of hydrofluoric acid (HF) and 2-propanol for the etching of the native oxide and passivating the dangling bond with hydrogen (H). Thereafter, highly promising photoactive materials CuO and ZnO were doped with the extracted Si-NPs. Finally, Si-NPs doped CuO and ZnO thin films were deposited on a cleaned glass substrate by spin-coating. X-Ray Diffraction (XRD) confirmed the amorphous nature of Si particles. Dynamic Light Scattering (DLS) demonstrates the size distribution of Si-NPs of ~120 nm for 180 minutes of sonication time. DLS results refer that the higher sonication time offers a lower particle size of Si with controlled rate. The addition of Si-NPs nanoparticles tailors the energy band alignment at the metal oxide/NP interface which provides efficient charge carrier transport and enhanced optical absorption (~20%) as revealed by UV-Vis Spectroscopy. Experimental results indicate that the extracted Si-NPs can be efficiently used in thin-film based optical and electronic devices.