An Interface Engineered Multicolor Photodetector Based on n‐Si(111)/TiO2 Nanorod Array Heterojunction. (29th January 2016) - Ji, Tao
Abstract : A multicolor photodetector based on the heterojunction of n‐Si(111)/TiO2 nanorod arrays responding to both ultraviolet (UV) and visible light is developed by utilizing interface engineering. The photodetector is fabricated via a consecutive process including chemical etching, magnetron sputtering, hydrothermal growth, and assembling. Under a small reverse bias (from 0 to ≈−2 V), only the photogenerated electrons in TiO2 are possible to tunnel through the low barrier of Δ E C, and the device only responses to UV light; as the reverse bias increases, the photogenerated holes in Si also begin to tunnel through the high barrier of Δ E V . As a result, the device is demonstrated to have the capacity to detect both UV and visible lights, which is useful in the fields of rapid detection and multicolor imaging. It has been also observed that the crystal orientation of Si affects the characteristics of bias‐controlled spectral response of the n‐Si/TiO2 heterojunctions. Abstract : A multicolor photodetector based on a n‐Si(111)/TiO2 nanorod array heterojunction is developed by utilizing interface engineering, responding to both ultraviolet and visible light by changing the applied bias.