Electrochemical Doping of Potassium in Hexagonal Boron Nitride toward Nanoelectronics

Potassium-doped hexagonal boron nitride (h-BN) was synthesized by electrochemical (EC) treatment in potassium hydroxide solution, and its electrical properties were measured. Back-gate field-effect transistors (FETs) of EC-treated h-BNs were fabricated using electron beam lithography and lift-off process. The drain current–gate voltage (ID–VG) characteristics showed that ID increased with VG, indicating n-type conduction. In contrast, the ID of pristine h-BN FETs was below the detection limit of the system. Results of advanced techniques such as annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, and electron energy loss spectroscopy indicate that agglomerated potassium atoms are intercalated between h-BN layers.