Deák P, Udvarhelyi P, Thiering G, Gali A. The kinetics of carbon pair formation in silicon prohibits reaching thermal equilibrium.
Nat Commun 2023;
14:361. [PMID:
36690635 PMCID:
PMC9870972 DOI:
10.1038/s41467-023-36090-2]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 01/13/2023] [Indexed: 01/24/2023] Open
Abstract
Thermal equilibrium is reached when the system assumes its lowest energy. This can be hindered by kinetic reasons; however, it is a general assumption that the ground state can be eventually reached. Here, we show that this is not always necessarily the case. Carbon pairs in silicon have at least three different configurations, one of them (B-configuration) is the G photoluminescence centre. Experiments revealed a bistable nature with the A-configuration. Electronic structure calculations predicted that the C-configuration is the real ground state; however, no experimental evidence was found for its existence. Our calculations show that the formation of the A- and B-configurations is strongly favoured over the most stable C-configuration which cannot be realized in a detectable amount before the pair dissociates. Our results demonstrate that automatized search for complex defects consisting of only the thermodynamically most stable configurations may overlook key candidates for quantum technology applications.
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