Exciton radiative lifetime in a monoatomic carbon chain

Linear carbon-based materials such as polyyne and cumulene oligomers provide a versatile platform for nano-physics and engineering. Direct gap quasi-1D polyyne structures are promising for the observation of strong and unusual excitonic effects arising due to the two-dimensional quantum confinement. Recently, we reported on the observation of sharp exciton peaks in low temperature photoluminescence spectra of polyyne chains (Kutrovskaya S et al 2020 Nano Lett. 20 6502-9). Here, we analyze the time-resolved optical response of this system. We extend the non-local dielectric response theory to predict the exciton radiative lifetime dependence on the band-gap value and on the length of the chain. A good agreement between the experiment and the theory is achieved.

Automated summary

Linear carbon-based materials such as polyyne and cumulene oligomers offer a versatile platform for nano-physics and engineering, with promising potential for observing strong and unusual excitonic effects. Recent research has shown sharp exciton peaks in low temperature photoluminescence spectra of polyyne chains, with the time-resolved optical response analyzed to predict exciton radiative lifetime dependence on band-gap value and chain length, achieving a good agreement between experiment and theory.