TY - JOUR
T1 - Evaluation of doped potassium concentrations in stacked Two-Layer graphene using Real-time XPS
AU - Ogawa, Shuichi
AU - Tsuda, Yasutaka
AU - Sakamoto, Tetsuya
AU - Okigawa, Yuki
AU - Masuzawa, Tomoaki
AU - Yoshigoe, Akitaka
AU - Abukawa, Tadashi
AU - Yamada, Takatoshi
N1 - Funding Information:
The authors wish to acknowledge Prof. Yuji Takakuwa (Tohoku University) for his useful advice in the SR experiments. This work was supported by the JSPS KAKENHI (Grant Nos. JP17KK00125, JP20K21136 and JP20H02191), Mayekawa Houonkai Foundation, and performed under the Cooperative Research Program of “Network Joint Research Center for Materials and Devices,” and the JAEA Fund for Exploratory Researches (Houga fund). The XPS measurements were performed using synchrotron radiation at beamline BL23SU of SPring-8 (Proposal Nos. 2020A3801, 2021A3801, 2021B3801).
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/12/15
Y1 - 2022/12/15
N2 - The immersion of graphene in potassium hydroxide solutions improves its electron mobility on SiO2/Si substrates. This has been attributed to doping with K atoms, but the K concentration xK has not been determined. Here, xK was determined with X-ray photoelectron spectroscopy using intense synchrotron radiation. The K 2p peak intensity decreased with increasing irradiation time. Curve fitting analysis was performed to quantitatively evaluate the change in xK with irradiation time. However, because the K 2p peak was affected by the asymmetric tail of the C 1 s peak, background removal and peak separation analysis were performed simultaneously using the “active Shirley” method. The change in xK was determined by real-time observations, and xK before irradiation was estimated to be 1.00 ± 0.09 mol %. Furthermore, the C 1 s spectrum shifted to lower binding energy with radiation exposure. This indicated that electron carriers in the graphene decreased because of K desorption.
AB - The immersion of graphene in potassium hydroxide solutions improves its electron mobility on SiO2/Si substrates. This has been attributed to doping with K atoms, but the K concentration xK has not been determined. Here, xK was determined with X-ray photoelectron spectroscopy using intense synchrotron radiation. The K 2p peak intensity decreased with increasing irradiation time. Curve fitting analysis was performed to quantitatively evaluate the change in xK with irradiation time. However, because the K 2p peak was affected by the asymmetric tail of the C 1 s peak, background removal and peak separation analysis were performed simultaneously using the “active Shirley” method. The change in xK was determined by real-time observations, and xK before irradiation was estimated to be 1.00 ± 0.09 mol %. Furthermore, the C 1 s spectrum shifted to lower binding energy with radiation exposure. This indicated that electron carriers in the graphene decreased because of K desorption.
KW - Active Shirley method
KW - Potassium doping
KW - Stacked two-layer graphene
KW - Synchrotron radiation
KW - XPS
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U2 - 10.1016/j.apsusc.2022.154748
DO - 10.1016/j.apsusc.2022.154748
M3 - Article
AN - SCOPUS:85137614927
SN - 0169-4332
VL - 605
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 154748
ER -