In2Se3 Visible/Near-IR Photodetector With Observation of Band-Edge in Spectral Response

We report on the demonstration of visible/near-IR high-performance photodetector based on exfoliated beta-Indium selenide (In2Se3) on sapphire with a clear signature of band edge in spectral responsivity at a wavelength of similar to 850-900 nm. Room temperature photoluminescence (PL) measurements also indicated a peak at similar to 900 nm confirming the band-edge. Devices with inter-digitated metal-semiconductor-metal (MSM) geometry exhibited a responsivity of 3.8 A/W (normalized to device area). A low dark current of 0.80 nA and a photo to dark current ratio of similar to 52 were measured when illuminated with 650 nm A specific detectivity of 1 x 10(10) cm Hz(0.5) W-1 at 650 nm and 6 x 10(8) cm Hz(0.5) W-1 at the band-edge of 900 nm were estimated. These results indicate the promise of beta-(In2Se3) for visible/near-IR detector applications.