Fully Encapsulated and Stable Black Phosphorus Field‐Effect Transistors

Black phosphorus (BP) has quickly gained popularity in the scientific community owing to its interesting semiconducting properties, such as direct bandgap, high mobility, and intrinsic ambipolar behavior. However, sensitivity oxygen, moisture, other air species restricted integration into active devices. Here, lithography-free via-encapsulation scheme fabricate fully-encapsulated BP-based field-effect transistors (FETs) is employed. The full encapsulation achieved by sandwiching BP layers between top bottom hexagonal boron nitride (hBN) layers; hBN passivating layer from environment acting a spacer suppressing charge transfer SiO2 substrate. embedded via-metal electrodes allow authors perform reliable electrical measurements of FETs. Based on these results, it found that electronic properties via-encapsulated FETs are significantly improved compared unencapsulated This further establishes via-contacting leads superior results graphene-hBN heterostructures bare combined with evaporated metal contacts (both use encapsulate BP) revealing higher lower hysteresis, long-term ambient-stability