Stability enhancement by hydrophobic anchoring and a cross-linked structure of a phospholipid copolymer film for medical devices

Uchida, Kazuto*; Masuda, Tsukuru*; Hara, Shintaro*; Matsuo, Yoichi*; Liu, Y.*; Aoki, Hiroyuki; Asano, Yoshihiko*; Miyata, Kazuki*; Fukuma, Takeshi*; Ono, Toshiya*; et al.

ACS Applied Materials & Interfaces, 16(30), p.39104 - 39116, 2024/07

https://doi.org/10.1021/acsami.4c07752

Defect-induced performance degradation of 4H-SiC Schottky barrier diode particle detectors

Iwamoto, Naoya; Johnson, B. C.; Hoshino, Norihiro*; Ito, Masahiko*; Tsuchida, Hidekazu*; Kojima, Kazutoshi*; Oshima, Takeshi

Journal of Applied Physics, 113(14), p.143714_1 - 143714_5, 2013/04

https://doi.org/10.1063/1.4801797

Defects in an electron-irradiated 6H-SiC diode studied by alpha particle induced charge transient spectroscopy; Their impact on the degraded charge collection efficiency

Iwamoto, Naoya*; Koizumi, Atsushi*; Onoda, Shinobu; Makino, Takahiro; Oshima, Takeshi; Kojima, Kazutoshi*; Koike, Shumpei*; Uchida, Kazuo*; Nozaki, Shinji*

Materials Science Forum, 717-720, p.267 - 270, 2012/05

https://doi.org/10.4028/www.scientific.net/MSF.717-720.267

In this study, we carried out an attempt to identify the defects responsible for the degraded charge collection efficiency of the 6H-SiC pn diode irradiated with 1 MeV electrons by the alpha particle induced charge transient spectroscopy. To form defects in the SiC crystal, one of the diodes was irradiated with 1 MeV electrons at a fluence of 110 /cm. Collected charges of the diodes were measured in room temperature using 5.486 MeV alpha particles from Am source. After the electron irradiation, the collected charge of the diode at a reverse bias of 100 V decreased to 84% of its initial value. In order to investigate the relationship between degradation of collected charge and defects in detail, time-dependent collected charges of the diodes were measured in temperature ranges from 170 K to 310 K. As a result, two distinct peaks labeled X and X are found for the electron-irradiated diode, and their activation energies are estimated to be 0.30 and 0.47 eV, respectively. These two peaks are considered to correspond to the defect levels introduced by the electron irradiation. In particular, when the diodes are used in room temperature, X is more critical to the charge collection than X.

Transient analysis of an extended drift region in a 6H-SiC diode formed by a single alpha particle strike and its contribution to the increased charge collection

Iwamoto, Naoya; Onoda, Shinobu; Makino, Takahiro; Oshima, Takeshi; Kojima, Kazutoshi*; Koizumi, Atsushi*; Uchida, Kazuo*; Nozaki, Shinji*

IEEE Transactions on Nuclear Science, 58(1), p.305 - 313, 2011/02

https://doi.org/10.1109/TNS.2010.2096432

no abstracts in English

Charge collection efficiency of 6H-SiC PN diodes degraded by low-energy electron irradiation

Iwamoto, Naoya; Onoda, Shinobu; Oshima, Takeshi; Kojima, Kazutoshi*; Koizumi, Atsushi*; Uchida, Kazuo*; Nozaki, Shinji*

Materials Science Forum, 645-648, p.921 - 924, 2010/00

Electron irradiation effects on the charge collection efficiency (CCE) of the 6H-SiC pn diodes were investigated. The diodes were irradiated with electrons at energies from 100 keV to 1 MeV. The value of CCE of the diodes using alpha particles compared before and after the electron irradiations. In the case of 100 keV electron, no significant change in CCE was observed. On the other hand, above 200 keV, the values of CCE decreased with increasing fluence. The degradation was larger with increasing incident electron energy.

Relation between Z center and the charge collection efficiency of SiC high-energy particle detectors

Iwamoto, Naoya; Johnson, B. C.; Hoshino, Norihiro*; Ito, Masahiko*; Tsuchida, Hidekazu*; Kojima, Kazutoshi*; Oshima, Takeshi

no journal, , 

no abstracts in English

Decreases in charge collection efficiencies of 6H-SiC diodes due to low-energy electron irradiations

Iwamoto, Naoya; Onoda, Shinobu; Oshima, Takeshi; Kojima, Kazutoshi*; Koizumi, Atsushi*; Uchida, Kazuo*; Nozaki, Shinji*

no journal, , 

no abstracts in English

Defects characterization of 4H-SiC pn diode by laplace DLTS

Koike, Shumpei*; Iwamoto, Naoya; Onoda, Shinobu; Oshima, Takeshi; Kojima, Kazutoshi*; Koizumi, Atsushi*; Ono, Hiroshi*; Uchida, Kazuo*; Nozaki, Shinji*

no journal, , 

no abstracts in English

Observation of negative-U centers in n-type 6H-SiC using laplace DLTS

Koizumi, Atsushi*; Markevich, V. P.*; Iwamoto, Naoya; Sasaki, Sho*; Koike, Shumpei*; Oshima, Takeshi; Kojima, Kazutoshi*; Kimoto, Tsunenobu*; Uchida, Kazuo*; Nozaki, Shinji*; et al.

no journal, , 

no abstracts in English