Quantifying the bulk yield of carbyne confined in different carbon nanotube hosts

Carbyne can be successfully synthesized inside carbon nanotubes with exceptionally high yield. However, the exact determination of its bulk yield remains challenging because of the lack of an available analysis method. Raman spectroscopy is the preferred method for the analysis of confined carbyne, as confined carbyne has the highest observed resonance Raman cross section. However, the resonance window is narrow and depends on the host carbon nanotube and its interaction with the confined carbyne, which results in challenges accounting for the bulk yield of confined carbyne in different environments. Here, we propose a model to quantify the yield of confined carbyne using distinct changes in the vibrational response induced by the anharmonic coupling between the carbon nanotube and the carbyne chain. This allows us to quantify the bulk yield of carbyne confined in different carbon nanotube environments without relying on the narrow resonance window of carbyne, paving the way for optimizing the bulk yield of confined carbyne and achieving the full growth potential.