Questioning the near-intrinsic thermal conductivity of suspended graphene membranes fabricated via a cyclododecane-based transfer method

A recent study by Wang et al. 1 reported a remarkably high thermal conductivity of 4914 W/m K near room temperature (338 K) in suspended graphene synthesized via chemical vapor deposition (CVD). This value notably exceeds all previous measurements for isotopically pure diamond 2 and graphene 3 and even surpasses theoretical predictions for pristine, infinitely large graphene sheets 4 . Wang et al. attribute this exceptional thermal conductivity to an optimized, contamination-free transfer process of their CVD-grown graphene 1 . However, based on our critical analysis of their data, we contend that the evidence presented does not substantiate this claim. Our assessment suggests that the actual thermal conductivity of their sample is substantially lower than reported, raising important questions about the reliability of these findings and the conditions necessary to achieve such high thermal transport in graphene.