Impact of radio-frequency power on the photoresponsivity enhancement of BaSi2 films formed by sputtering
Taira Nemoto, Ryota Koitabashi, Masami Mesuda, Kaoru Toko and Takashi Suemasu
Applied Physics Express
We fabricated BaSi2 films on Si substrates at 600 °C by sputtering under various radio-frequency powers (PBaSi2). Rutherford backscattering spectrometry revealed that the atomic ratio of Ba and Si reaching the substrate remained unchanged regardless of PBaSi2. However, the photoresponsivity decreased with PBaSi2. This is ascribed to the increase of vacancy-type defects from the peak shift of the Ag mode, the most intense Raman line, to lower wavenumbers with PBaSi2. The photoresponsivity reached a maximum of 0.67 A W-1 at a bias voltage of 0.1 V at PBaSi2 = 20 W, the highest ever achieved for undoped BaSi2 films.
Raman Imaging Spectroscopy, Photoresistivity, Sputtering, BaSi2