Influence of doping on non-equilibrium carrier dynamics in graphene
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arXiv
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| Main Authors: | , , , , , , , |
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| Format: | Preprint |
| Published: |
2025
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| _version_ | 1866913783118561280 |
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| author | Weigl, Leonard Gradl, Johannes Richter, Peter Seyller, Thomas Convertino, Domenica Forti, Stiven Coletti, Camilla Gierz, Isabella |
| author_facet | Weigl, Leonard Gradl, Johannes Richter, Peter Seyller, Thomas Convertino, Domenica Forti, Stiven Coletti, Camilla Gierz, Isabella |
| contents | Controlling doping is key to optimizing graphene for high-speed electronic and optoelectronic devices. However, its impact on non-equilibrium carrier lifetimes remains debated. Here, we systematically tune the doping level of quasi-freestanding epitaxial graphene on SiC(0001) via potassium deposition and probe its ultrafast carrier dynamics directly in the band structure using time- and angle-resolved photoemission spectroscopy (trARPES). We find that increased doping lowers both the peak electronic temperature and the cooling rate of Dirac carriers, which we attribute to higher electronic heat capacity and reduced phonon emission phase space. Comparing quasi-freestanding graphene with graphene on a carbon buffer layer reveals faster relaxation in the latter, likely due to additional phonon modes being available for heat dissipation. These findings offer new insights for optimizing graphene in electronic and photonic technologies. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2504_05744 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Influence of doping on non-equilibrium carrier dynamics in graphene Weigl, Leonard Gradl, Johannes Richter, Peter Seyller, Thomas Convertino, Domenica Forti, Stiven Coletti, Camilla Gierz, Isabella Mesoscale and Nanoscale Physics Materials Science Controlling doping is key to optimizing graphene for high-speed electronic and optoelectronic devices. However, its impact on non-equilibrium carrier lifetimes remains debated. Here, we systematically tune the doping level of quasi-freestanding epitaxial graphene on SiC(0001) via potassium deposition and probe its ultrafast carrier dynamics directly in the band structure using time- and angle-resolved photoemission spectroscopy (trARPES). We find that increased doping lowers both the peak electronic temperature and the cooling rate of Dirac carriers, which we attribute to higher electronic heat capacity and reduced phonon emission phase space. Comparing quasi-freestanding graphene with graphene on a carbon buffer layer reveals faster relaxation in the latter, likely due to additional phonon modes being available for heat dissipation. These findings offer new insights for optimizing graphene in electronic and photonic technologies. |
| title | Influence of doping on non-equilibrium carrier dynamics in graphene |
| topic | Mesoscale and Nanoscale Physics Materials Science |
| url | https://arxiv.org/abs/2504.05744 |