Abstract
Single crystalline p- A nd n-type Si(100) wafers were severely deformed by high-pressure torsion (HPT) under a nominal pressure of 24 GPa. The HPT-processed samples consisted of metastable phases of body-centered-cubic Si-III and rhombohedral Si-XII, as well as diamond-cubic Si-I and amorphous phases. The photoemission spectroscopy using synchrotron radiation revealed that the valence band edge of the HPT-processed p- A nd n-type Si samples was located at ∼0.3 eV. Successive annealing in vacuum up to 200 °C led to the valence-band edge shift by ∼0.4 eV for both p- A nd n-type Si, and the disappearance of Si-III and Si-XII. These results indicated that the Si-III and Si-XII phases in the HPT-processed samples have smaller band gap than that of Si-I, and suggested that the valence-band edge shift after annealing is due to the mixture of Si-I and Si-IV phases in addition to the mid-gap pinning of the Fermi level.
| Original language | English |
|---|---|
| Article number | 101904 |
| Journal | Applied Physics Letters |
| Volume | 113 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Sep 3 2018 |
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All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)
Cite this
Crystal and electronic structural changes during annealing in severely deformed Si containing metastable phases formed by high-pressure torsion. / Ikoma, Yoshifumi; Chon, Bumsoo; Yamasaki, Terumasa; Takahashi, Kazutoshi; Saito, Katsuhiko; Guo, Qixin; Horita, Zenji.
In: Applied Physics Letters, Vol. 113, No. 10, 101904, 03.09.2018.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Crystal and electronic structural changes during annealing in severely deformed Si containing metastable phases formed by high-pressure torsion
AU - Ikoma, Yoshifumi
AU - Chon, Bumsoo
AU - Yamasaki, Terumasa
AU - Takahashi, Kazutoshi
AU - Saito, Katsuhiko
AU - Guo, Qixin
AU - Horita, Zenji
PY - 2018/9/3
Y1 - 2018/9/3
N2 - Single crystalline p- A nd n-type Si(100) wafers were severely deformed by high-pressure torsion (HPT) under a nominal pressure of 24 GPa. The HPT-processed samples consisted of metastable phases of body-centered-cubic Si-III and rhombohedral Si-XII, as well as diamond-cubic Si-I and amorphous phases. The photoemission spectroscopy using synchrotron radiation revealed that the valence band edge of the HPT-processed p- A nd n-type Si samples was located at ∼0.3 eV. Successive annealing in vacuum up to 200 °C led to the valence-band edge shift by ∼0.4 eV for both p- A nd n-type Si, and the disappearance of Si-III and Si-XII. These results indicated that the Si-III and Si-XII phases in the HPT-processed samples have smaller band gap than that of Si-I, and suggested that the valence-band edge shift after annealing is due to the mixture of Si-I and Si-IV phases in addition to the mid-gap pinning of the Fermi level.
AB - Single crystalline p- A nd n-type Si(100) wafers were severely deformed by high-pressure torsion (HPT) under a nominal pressure of 24 GPa. The HPT-processed samples consisted of metastable phases of body-centered-cubic Si-III and rhombohedral Si-XII, as well as diamond-cubic Si-I and amorphous phases. The photoemission spectroscopy using synchrotron radiation revealed that the valence band edge of the HPT-processed p- A nd n-type Si samples was located at ∼0.3 eV. Successive annealing in vacuum up to 200 °C led to the valence-band edge shift by ∼0.4 eV for both p- A nd n-type Si, and the disappearance of Si-III and Si-XII. These results indicated that the Si-III and Si-XII phases in the HPT-processed samples have smaller band gap than that of Si-I, and suggested that the valence-band edge shift after annealing is due to the mixture of Si-I and Si-IV phases in addition to the mid-gap pinning of the Fermi level.
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U2 - 10.1063/1.5038160
DO - 10.1063/1.5038160
M3 - Article
AN - SCOPUS:85053001132
VL - 113
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 10
M1 - 101904
ER -