Surface Transfer Doping of Cubic Boron Nitride Films by MoO3 and Tetrafluoro-tetracyanoquinodimethane (F4-TCNQ).
Cubic boron nitride (cBN) has strong potential for the applications in high-temperature and high-power electronics and deep ultraviolet devices due to its outstanding combined physical and chemical properties. P-type surface transfer doping of heteroepitaxial cBN films was achieved by employing MoO3 and tetrafluoro-tetracyanoquinodimethane (F4-TCNQ) as the surface dopants. The surface conductivities of hydrogenated cBN films increased by 3-6 orders after the deposition of surface dopants. The photoemission spectroscopy (PES) measurements revealed the variation of electronic structures at the interface regions, which suggested that the electron transfer from cBN films to the surface dopants induced hole accumulation at the cBN surface and the increase of surface conductivity. Based on the PES results, the energy level diagrams at MoO3/cBN and F4-TCNQ/cBN interfaces were determined. The achievement provided a potential approach for fabricating cBN-based electronic devices, especially on micrometer and nanometer scales.
Center of Super-Diamond and Advanced Films (COSDAF), and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.
Bin
B
He
Center of Super-Diamond and Advanced Films (COSDAF), and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.
Tsz-Wai
TW
Ng
Center of Super-Diamond and Advanced Films (COSDAF), and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.
Ming-Fai
MF
Lo
Center of Super-Diamond and Advanced Films (COSDAF), and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.
Chun-Sing
CS
Lee
Center of Super-Diamond and Advanced Films (COSDAF), and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.
Wenjun
W
Zhang
band bending; cubic boron nitride (cBN); electronic structure; interface dipole; photoemission spectroscopy (PES); surface transfer doping