In application of graphene to real electronics, understanding the mechanism of the electrical breakdown of the graphene in harsh environments should precede many activities in tamed conditions. In this article, we report the unusual structural evolution of microbridge graphene in air near the electrical current-breakdown limit. In-situ micro-Raman study revealed that Joule heating near the electrical breakdown gave rise to a substantial structural evolution: A previously unknown broad amorphous-like and partially reversible phase at an on-and off-current of ∼3.0 × 108 A/cm2, which finally drove the phase to the electrical current-breakdown. Our calculations suggest that the phase originates from the broken symmetry caused by defect formations during Joule heating. In particular, these formations are bonds of carbon-oxygen and vacancies-oxygen. A collection of energetically favorable vacancies-oxygen pairs results in porous graphene, and its evolution can be the key to understanding how the breakdown starts and propagates in graphene under high current density in air.
Bibliographical noteFunding Information:
Research at Yonsei University was supported in part by Samsung Electronics Co. , by Basic Science Research Program (2014R1A2A1A11050290 and 2013R1A1A2013745) through the National Research Foundation of Korea (NRF) funded by the Korean government (MOE and MSIP) , by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) ( NRF-2014R1A2A1A11050290 ), and by Creative Materials Discovery Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning ( 2015M3D1A1070465 ). Research at Ewha University was supported in part by the NRF Grant (No. 2015001948 ) and the Joint Research Project under the Korea-Japan Basic Scientific Cooperation Program ( 2013K2A2A4003603 ). Work at KIST was supported by the Industrial Strategic Technology Development Program (Grant No. 10041589) funded by the MOTIE of Korea and KIST Institutional Project ( 2E25372 ). Work at Seoul National University was supported in part by the Global Research Lab (GRL) Program (2011-0021972) through the NRF funded by the Korean government (MEST and MKE) .
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All Science Journal Classification (ASJC) codes
- Materials Science(all)