Pump-Probe X-ray Photoemission Spectroscopy of Free-Standing Graphane

Condensed Matter

article

Roberto Costantini¹  Dario Marchiani³  Maria Grazia Betti³  Carlo Mariani³  Samuel Jeong⁵  Yoshikazu Ito⁵  Alberto Morgante¹  Martina Dell’Angela² 

[1] Dipartimento di Fisica, Università di Trieste;Istituto Officina dei Materiali CNR-IOM;Dipartimento di Fisica, Università di Roma “La Sapienza”;INFN Sezione di Roma;Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba

关键词: nanoporous graphene;    graphane;    pump-probe spectroscopy;    time-resolved spectroscopy;    X-ray photoelectron spectroscopy;   

DOI  :  10.3390/condmat8020031

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

Free-standing nanoporous graphene was hydrogenated at about 60 at.% H uptake, as determined by the emerging of the sp3 bonding component in the C 1s core level investigated by high-resolution X-ray photoelectron spectroscopy (XPS). Fully unsupported graphane was investigated by XPS under optical excitation at 2.4 eV. At a laser fluence of 1.6 mJ/cm2, a partial irreversible dehydrogenation of the graphane was observed, which could be attributed either to the local temperature increase or to a photo-induced softening of the H-to-C stretching mode. The sub-ns dynamics of the energy shift and peak broadening of the C 1s core level revealed two different decay constants: 210 ps and 130 ps, respectively, the former associated with photovoltage dynamics and the latter with thermal heating on a time scale comparable with the synchrotron temporal resolution.

【 授权许可】

CC BY