کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5395805 | 1505730 | 2015 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Ramifications of optical pumping on the interpretation of time-resolved photoemission experiments on graphene
ترجمه فارسی عنوان
تکرار کردن پمپاژ نوری در تفسیر تجربیات فتوشیمیایی حل شده بر روی گرافن
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کلمات کلیدی
گرافن، عکسبرداری زمان و زاویه حل شده، هزینه فضا، الکترون های داغ،
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
چکیده انگلیسی
In pump-probe time and angle-resolved photoemission spectroscopy (TR-ARPES) experiments the presence of the pump pulse adds a new level of complexity to the photoemission process in comparison to conventional ARPES. This is evidenced by pump-induced vacuum space-charge effects and surface photovoltages, as well as multiple pump excitations due to internal reflections in the sample-substrate system. These processes can severely affect a correct interpretation of the data by masking the out-of-equilibrium electron dynamics intrinsic to the sample. In this study, we show that such effects indeed influence TR-ARPES data of graphene on a silicon carbide (SiC) substrate. In particular, we find a time- and laser fluence-dependent spectral shift and broadening of the acquired spectra, and unambiguously show the presence of a double pump excitation. The dynamics of these effects is slower than the electron dynamics in the graphene sample, thereby permitting us to deconvolve the signals in the time domain. Our results demonstrate that complex pump-related processes should always be considered in the experimental setup and data analysis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Electron Spectroscopy and Related Phenomena - Volume 200, April 2015, Pages 340-346
Journal: Journal of Electron Spectroscopy and Related Phenomena - Volume 200, April 2015, Pages 340-346
نویسندگان
Søren Ulstrup, Jens Christian Johannsen, Federico Cilento, Alberto Crepaldi, Jill A. Miwa, Michele Zacchigna, Cephise Cacho, Richard T. Chapman, Emma Springate, Felix Fromm, Christian Raidel, Thomas Seyller, Phil D.C. King, Fulvio Parmigiani,