An investigation on the interplay between strain and defects on the thermal conductivity of monolayer graphene

Strain engineering is rapidly gaining momentum as a method to tuning the thermal properties of materials. We have performed extensive molecular dynamics studies on the thermal properties of defective single layer graphene (d-SLG) to understand its effects on its thermal conductivity. We have created a model of d-SLG, and we have then applied a varying strain amount onto the graphene model to determine if it is possible to rectify the defect-induced thermal conductivity reduction. Using a Tersoff manybody potential, we have calculated the thermal conductivity of our model. Our results show a quantitative ability of strain to rectify thermal conductivity reductions up to a point. Our simulation found that there are 2 points of interest, 5% ε<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> and, 10% ε<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> and ε<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</inf>. Compared to their unstrained counterparts, 5% ε<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> on 0.3% d-SLG shows a 192% increase in λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pvr</inf>. We also found that 10% ε<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> and ε<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</inf> on 0.6% d-SLG shows a 246% and 323% increase in λ-ovr. We have then explained this phenomenon using the models of phonon-phonon and phonon-defect scattering. We believe this research can be applied to different 2D materials and advance our understanding of thermal transport in these low-dimensional materials in heat management applications.