Improved omnidirectional polarisation‐insensitive optical absorption and photoelectrochemical water splitting using aperiodic and tapered slanted, kinked and straight silicon nanowires

We have experimentally demonstrated that slanted, kinked and straight silicon nanowire arrays form a broadband omnidirectional light-harvesting structure. The unique design of kinked and slanted nanowires allows them to trap more light effectively across a wide wavelength range than straight silicon nanowires (SiNWs). We report that the light absorption in slanted, kinked and straight wires is enhanced by controlling their geometrical parameters. The p-type SiNWs have less reflection than n-type SiNWs due to their larger porosity gradient structure. Aperiodic and tapered slanted, kinked and straight SiNWs are remarkably photoactive and promising low-cost materials for photoelectrochemical water splitting applications.