Growth, characterization and theoretical optical properties of polycrystalline n-silicon thin films for oxide-silicon tandem cells

Abstract

With the decline in fossil fuels, hydrogen-based alternatives provide a reliable and clean source for sustainable energy generation. In these endeavors, photochemical splitting for hydrogen production through tandem cells has been the source of much theoretical and experimental research in science. Much focus has been placed on interfacial band gap engineering as one of the most promising routes in the generation of hydrogen. This present work explores sputtering of n-silicon to form the active electrode in a n-Si ∣ n-TiO2 tandem cell and investigates the effect of variations in sputtering and post sputtering treatment parameters (rapid thermal annealing and long cycle annealing) for successful deposition of crystalline Silicon. The samples were successfully characterized via Raman Spectroscopy, x-ray Diffraction and Optical Transmission Spectroscopy to ascertain prevalent crystalline order and optical band gap, under different sputtering and post-sputtering conditions. Relevant conclusions to ascertain the best possible n-Si deposition parameters indicated the use of post-sputtering annealing to induce and enhance crystallinity but to be cautious as not to incur the loss of Si during the annealing process.