TY - JOUR
T1 - Effects of Boron Doping on the Bulk and Surface Acoustic Phonons in Single-Crystal Diamond
AU - Guzman, Erick
AU - Kargar, Fariborz
AU - Angeles, Frank
AU - Meidanshahi, Reza Vatan
AU - Grotjohn, Timothy
AU - Hardy, Aaron
AU - Muehle, Matthias
AU - Wilson, Richard B.
AU - Goodnick, Stephen M.
AU - Balandin, Alexander A.
N1 - Publisher Copyright:
© 2022 American Chemical Society.
PY - 2022/9/21
Y1 - 2022/9/21
N2 - We report the results of the investigation of bulk and surface acoustic phonons in the undoped and boron-doped single-crystal diamond films using the Brillouin-Mandelstam light scattering spectroscopy. The evolution of the optical phonons in the same set of samples was monitored with Raman spectroscopy. It was found that the frequency and the group velocity of acoustic phonons decrease nonmonotonically with the increasing boron doping concentration, revealing pronounced phonon softening. The change in the velocity of the shear-horizontal and the high-frequency pseudo-longitudinal acoustic phonons in the degenerately doped diamond, as compared to that in the undoped diamond, was as large as ∼15% and ∼12%, respectively. As a result of boron doping, the velocity of the bulk longitudinal and transverse acoustic phonons decreased correspondingly. The frequency of the optical phonons was unaffected at low boron concentration but experienced a strong decrease at the high doping level. The density-functional-theory calculations of the phonon band structure for the pristine and highly doped samples confirm the phonon softening as a result of boron doping in diamond. The obtained results have important implications for thermal transport in heavily doped diamond, which is a promising material for ultra-wide-band-gap electronics.
AB - We report the results of the investigation of bulk and surface acoustic phonons in the undoped and boron-doped single-crystal diamond films using the Brillouin-Mandelstam light scattering spectroscopy. The evolution of the optical phonons in the same set of samples was monitored with Raman spectroscopy. It was found that the frequency and the group velocity of acoustic phonons decrease nonmonotonically with the increasing boron doping concentration, revealing pronounced phonon softening. The change in the velocity of the shear-horizontal and the high-frequency pseudo-longitudinal acoustic phonons in the degenerately doped diamond, as compared to that in the undoped diamond, was as large as ∼15% and ∼12%, respectively. As a result of boron doping, the velocity of the bulk longitudinal and transverse acoustic phonons decreased correspondingly. The frequency of the optical phonons was unaffected at low boron concentration but experienced a strong decrease at the high doping level. The density-functional-theory calculations of the phonon band structure for the pristine and highly doped samples confirm the phonon softening as a result of boron doping in diamond. The obtained results have important implications for thermal transport in heavily doped diamond, which is a promising material for ultra-wide-band-gap electronics.
KW - Brillouin light scattering
KW - Raman spectroscopy
KW - diamond
KW - phonon softening
KW - ultra-wide-band-gap materials
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U2 - 10.1021/acsami.2c10879
DO - 10.1021/acsami.2c10879
M3 - Article
C2 - 36083635
AN - SCOPUS:85138064566
SN - 1944-8244
VL - 14
SP - 42223
EP - 42231
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 37
ER -