1. Guangdong
Provincial Key Laboratory of Thermal Management Engineering and Materials,
Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, P. R. China
2. Tsinghua-Berkeley
Shenzhen Institute (TBSI), Tsinghua University, Shenzhen 518055, P. R. China
3. Engineering
Laboratory for Functionalized Carbon Materials and Shenzhen Key Laboratory
for Graphene-based Materials, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, P. R. China