Characterization of the electric transport properties of black phosphorous back-gated field-effect transistors

Abstract

We use thin layers of exfoliated black phosphorus to realize back-gated field-effect transistors in which the Si/SiO2 substrate is exploited as gate electrode. To prevent the detrimental effect of the air exposure the devices are protected by Poly(methyl methacrylate). We report the observation of an improved contact resistance at the interface between the layered material and the metal contact by electrical conditioning. We also demonstrate the existence of a hysteresis in the transfer characteristics that improves by increasing the gate voltage sweep range. Finally, we prove the suitability of such transistors as memory devices.

Black Phosphorus Nanosheets in Field Effect Transistors with Ni and NiCr Contacts

“…[8][9][10] Thanks to the high charge-carrier mobility, few-layer BP can be used as channel material of high-speed field effect transistors (FETs). [1,9,[11][12][13][14] Moreover, the tunable and direct bandgap, ranging from infrared to visible frequencies, together with the high absorption coefficient in the ultra-violet (UV) region, make BP a suitable material for optoelectronic applications, such as photodetectors [15,16] and photovoltaic devices. [17][18][19] BP's electronic, optical, and thermal transport properties are highly anisotropic since it presents a strong structural in-plane anisotropy.…”