%0 Journal Article %1 penfold2018revealing %A Penfold, Thomas J. %A Szlachetko, Jakub %A Santomauro, Fabio G. %A Britz, Alexander %A Gawelda, Wojciech %A Doumy, Gilles %A March, Anne Marie %A Southworth, Stephen H. %A Rittmann, Jochen %A Abela, Rafael %A Chergui, Majed %A Milne, Christopher J. %D 2018 %J Nature Communications %K metaloxides traps x-ray_spectroscopy %N 1 %P 478-- %R 10.1038/s41467-018-02870-4 %T Revealing hole trapping in zinc oxide nanoparticles by time-resolved X-ray spectroscopy %U https://doi.org/10.1038/s41467-018-02870-4 %V 9 %X Nanostructures of transition metal oxides, such as zinc oxide, have attracted considerable interest for solar-energy conversion and photocatalysis. Both applications are sensitive to the transport and trapping of photoexcited charge carriers. The probing of electron trapping has recently become possible using time-resolved element-sensitive methods, such as X-ray spectroscopy. However, valence-band-trapped holes have so far escaped observation. Herein we use X-ray absorption spectroscopy combined with a dispersive X-ray emission spectrometer to probe the charge carrier relaxation and trapping processes in zinc oxide nanoparticles after above band-gap photoexcitation. Our results, supported by simulations, demonstrate that within 80 ps, photoexcited holes are trapped at singly charged oxygen vacancies, which causes an outward displacement by ~15% of the four surrounding zinc atoms away from the doubly charged vacancy. This identification of the hole traps provides insight for future developments of transition metal oxide-based nanodevices.

@article{penfold2018revealing, abstract = {Nanostructures of transition metal oxides, such as zinc oxide, have attracted considerable interest for solar-energy conversion and photocatalysis. Both applications are sensitive to the transport and trapping of photoexcited charge carriers. The probing of electron trapping has recently become possible using time-resolved element-sensitive methods, such as X-ray spectroscopy. However, valence-band-trapped holes have so far escaped observation. Herein we use X-ray absorption spectroscopy combined with a dispersive X-ray emission spectrometer to probe the charge carrier relaxation and trapping processes in zinc oxide nanoparticles after above band-gap photoexcitation. Our results, supported by simulations, demonstrate that within 80 ps, photoexcited holes are trapped at singly charged oxygen vacancies, which causes an outward displacement by ~15% of the four surrounding zinc atoms away from the doubly charged vacancy. This identification of the hole traps provides insight for future developments of transition metal oxide-based nanodevices.}, added-at = {2018-07-04T11:20:42.000+0200}, author = {Penfold, Thomas J. and Szlachetko, Jakub and Santomauro, Fabio G. and Britz, Alexander and Gawelda, Wojciech and Doumy, Gilles and March, Anne Marie and Southworth, Stephen H. and Rittmann, Jochen and Abela, Rafael and Chergui, Majed and Milne, Christopher J.}, biburl = {https://www.bibsonomy.org/bibtex/262015767cac3eca4856dda2e1a8dca3a/bretschneider_m}, doi = {10.1038/s41467-018-02870-4}, interhash = {7b3670b462be0877c1581fd0a9a715ee}, intrahash = {62015767cac3eca4856dda2e1a8dca3a}, issn = {20411723}, journal = {Nature Communications}, keywords = {metaloxides traps x-ray_spectroscopy}, number = 1, pages = {478--}, refid = {Penfold2018}, timestamp = {2018-07-04T11:20:42.000+0200}, title = {Revealing hole trapping in zinc oxide nanoparticles by time-resolved X-ray spectroscopy}, url = {https://doi.org/10.1038/s41467-018-02870-4}, volume = 9, year = 2018 }