High Performance Black Phosphorus Electronic and Photonic Devices with HfLaO Dielectric

As an emerging two-dimensional material, few-layer black phosphorus (BP) shows great potential in nanoelectronics and nanophotonics due to its high carrier velocity. However, non-optimized gate dielectrics often degrade the performance of BP devices severely. In this letter, we demonstrate high-performance BP devices using a novel HfLaO as back gate dielectric with improved interface quality. High current exceeding 1.15 mA/ $\mu \text{m}$ has been achieved at 20 K for BP transistors with improved noise spectral density. Moreover, BP photodetectors with a record high photoresponsivity up to $1.5\times 10^{8}$ A/W and fast response time of $10~\mu \text{s}$ at 300 K are demonstrated. Excellent photoresponse in a broadband spectrum range from 514 to 1800 nm at 70 K has also been achieved.