Femtosecond Charge Density Modulations in Photoexcited CuWO4

Yohei Uemura, Ahmed S.M. Ismail, Sang Han Park, Soonnam Kwon, Minseok Kim, Yasuhiro Niwa, Hiroki Wadati, Hebatalla Elnaggar, Federica Frati, Ties Haarman, Niko Höppel, Nils Huse, Yasuyuki Hirata, Yujun Zhang, Kohei Yamagami, Susumu Yamamoto, Iwao Matsuda, Tetsuo Katayama, Tadashi Togashi, Shigeki OwadaMakina Yabashi, Ufuk Halisdemir, Gertjan Koster, Toshihiko Yokoyama, Bert M. Weckhuysen, Frank M.F. De Groot*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Copper tungstate (CuWO4) is an important semiconductor with a sophisticated and debatable electronic structure that has a direct impact on its chemistry. Using the PAL-XFEL source, we study the electronic dynamics of photoexcited CuWO4. The Cu L3 X-ray absorption spectrum shifts to lower energy upon photoexcitation, which implies that the photoexcitation process from the oxygen valence band to the tungsten conduction band effectively increases the charge density on the Cu atoms. The decay time of this spectral change is 400 fs indicating that the increased charge density exists only for a very short time and relaxes electronically. The initial increased charge density gives rise to a structural change on a time scale longer than 200 ps.

Original languageEnglish
Pages (from-to)7329-7336
Number of pages8
JournalThe Journal of physical chemistry C
Issue number13
Early online date26 Mar 2021
Publication statusPublished - 8 Apr 2021

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