Chloroform-Assisted Rapid Growth of Vertical Graphene Array and Its Application in Thermal Interface Materials

With the continuous progress in electronic devices, thermal interface materials (TIMs) are urgently needed for the fabrication of integrated circuits with high reliability and performance. Graphene as a wonderful additive is often added into polymer to build composite TIMs. However, owing to the lack of a specific design of the graphene skeleton, thermal conductivity of graphene-based composite TIMs is not significantly improved. Here a chloroform-assisted method for rapid growth of vertical graphene (VG) arrays in electric field-assisted plasma enhanced chemical vapor deposition (PECVD) system is reported. Under the optimum intensity and direction of electric field and by introducing the highly electronegative chlorine into the reactor, the record growth rate of 11.5 mu m h(-1) is achieved and VG with a height of 100 mu m is successfully synthesized. The theoretical study for the first time reveals that the introduction of chlorine accelerates the decomposition of methanol and thus promotes the VG growth in PECVD. Finally, as an excellent filler framework in polymer matrix, VG arrays are used to construct a free-standing composite TIM, which yields a high vertical thermal conductivity of 34.2 W m(-1) K-1 at the graphene loading of 8.6 wt% and shows excellent cooling effect in interfacial thermal dissipation of light emitting diode.

Automated summary

This study reports a chloroform-assisted method for rapid growth of vertical graphene (VG) arrays in an electric field-assisted plasma enhanced chemical vapor deposition (PECVD) system, aiming to improve the thermal conductivity of graphene-based composite thermal interface materials (TIMs). The experimental results indicate that under the optimum intensity and direction of the electric field, and by introducing highly electronegative chlorine into the reactor, a record growth rate and a successful synthesis of 100 μm high VG are achieved. The theoretical study reveals, for the first time, that the introduction of chlorine can accelerate the decomposition of methanol and thus promote the growth of VG. Finally, a free-standing composite TIM using VG arrays as an excellent filler framework in a polymer matrix is constructed, which exhibits a high vertical thermal conductivity and an excellent cooling effect in the interfacial thermal dissipation of a light emitting diode.