TiO2 nanoparticles and silicon nanowires hybrid device: Role of interface on electrical, dielectric, and photodetection properties

We report ∼12, 5, 12, 100, and 70 times enhancement of external quantum efficiency, detectivity, responsivity, AC conductivity, and overall dielectric constant (ε′), respectively of hybrid silicon nanowires (SiNWs) and titania (TiO2) nanoparticles (NPs) device as compared to SiNWs only device. Devices show persistent photoconductivity. Metal assisted chemical etching and co-precipitation method were used to prepare SiNWs (length ∼40 μm, diameter ∼30–400 nm) and TiO2 NPs (diameter ∼50 nm), respectively. Formation of acceptor like states at NPs and SiNWs interface improves electrical properties. Presence of low refractive index TiO2 around SiNWs causing funneling of photon energy into SiNWs improves photodetection.