Refine your search:     
Report No.
 - 
Search Results: Records 1-4 displayed on this page of 4
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Detection of molecular oxygen adsorbate during room-temperature oxidation of Si(100)2$$times$$1 surface; In situ synchrotron radiation photoemission study

Yoshigoe, Akitaka; Yamada, Yoichi*; Taga, Ryo*; Ogawa, Shuichi*; Takakuwa, Yuji*

Japanese Journal of Applied Physics, 55(10), p.100307_1 - 100307_4, 2016/09

 Times Cited Count:1 Percentile:6.36(Physics, Applied)

Synchrotron radiation photoelectron spectroscopy during the oxidation of the Si(100)2$$times$$1 surface at room temperature revealed the existence of the molecularly adsorbed oxygen, which was considered to be absent. The O 1s spectra was found to be similar to that of the oxidation of Si(111)7$$times$$7 surfaces. Also the molecular oxygen was appeared after the initial surface oxides, indicating that this was not a precursor for dissociation oxygen adsorption onto the clean surface. We have proposed presumable structural models for atomic configurations, where the molecular oxygen was resided on the oxidized silicon with two oxygen atoms at the backbonds.

Oral presentation

Detection on molecularly oxygen adsorbate during room-temperature oxidation at Si(100) surface; Synchrotron radiation light shed light on issue over 3 decades

Yoshigoe, Akitaka; Taga, Ryo*; Ogawa, Shuichi*; Takakuwa, Yuji*

no journal, , 

In this conference, the experimental evidence on the existence of molecularly adsorbed oxygen during the oxidation of Si(100)2$$times$$1 surface, which was considered to be absent, is reported. Synchrotron radiation photoelectron spectroscopy measurements was used to reveal its presence during the oxidation at room temperature and -150$$^{circ}$$C.

Oral presentation

Comparison of initial oxidation kinetics between p- and n-type Si(001) surfaces studied by real-time photoelectron spectroscopy

Sekihata, Yuki*; Ogawa, Shuichi*; Yoshigoe, Akitaka; Taga, Ryo*; Ishizuka, Shinji*; Takakuwa, Yuji*

no journal, , 

In this study, we investigated the oxidation reaction kinetics on p- and n-type Si surfaces using real-time ultraviolet photoelectron spectroscopy. In the room temperature oxidation, it is found that oxidation reaction coefficient on n-Si(001) is larger than that on p-Si(001). The work function of the n-Si(001) surface shows negative value but p-Si(001) is positive value. From this result, we can estimate the adsorption positions of O atoms. O atoms have a negative charge in the bond of Si-O, so it can be assumed that oxygen is placed on the n-Si(001) surfaces, but it is subsurface in case of the p-Si(001) surface. In case of n-Si(001) substrates, the doped electrons spill out into the surface because many electrons exist in the substrate. As the result, oxidation reaction is promoted in the n-Si(001) surface. From these results, we found that there is a difference of oxidation kinetics depending on the conductivity.

Oral presentation

Valence band evaluation of graphene using in-situ photoelectron spectroscopy with non-monochromatic He I line

Ogawa, Shuichi*; Yamada, Takatoshi*; Taga, Ryo*; Yoshigoe, Akitaka; Takakuwa, Yuji*

no journal, , 

The molecular adsorption on graphene causes the modulation of conductivity of graphene, so that the application of graphene for gas sensors are expected. To evaluate the type of conductivity of graphene by photoelectron spectroscopy (PES), the angle-resolved PES is widely used. However, ARPES measurements have been performed usually in synchrotron facility or using monochromatic ultraviolet light. In this study, we try to evaluate the valence band of graphene using angle-integrated PES using non-monochromatic He I line in order to evaluate the changes of valence band of graphene during adsorption and/or desorption of molecules. As summary, we can measure the changes of shift of Fermi level depending on the temperature by using filter based on Fourier transform. This change is caused by desorption of absorbed molecules on graphene, and we can follow up the change because of using high-intensity non-monochromatic He I resonance line.

4 (Records 1-4 displayed on this page)
  • 1