An ultraviolet sensor comprises a glass substrate, a semiconductor structure, an electrode layer and a thin film metallic glass. The semiconductor structure comprises a semiconductor seed layer formed on the glass substrate and a plurality of semiconductor nanostructures formed on the semiconductor seed layer. The electrode layer is formed between the semiconductor seed layer and the plurality of semiconductor nanostructures. The thin film metallic glass is in contact with the semiconductor structure, wherein an interface between the thin film metallic glass and the semiconductor structure forms a Schottky barrier junction to inhibit dark current and increase signal-to-noise ratio.