Toward clean and crackless polymer-assisted transfer of CVD-grown graphene and its recent advances in GFET-based biosensors

Ever since the more than decade-old discovery of the mechanical exfoliation method for graphene isolation, this miraculous 2-dimensional material is still widely used in various applications because of its exceptional electron mobility and thermal conductivity. Graphene, commonly grown on a metallic substrate using chemical vapor deposition (CVD), needs to be transferred onto dielectric substrates compatible with complementary metal oxide–semiconductor (CMOS) technology for various electronic and optical applications. However, the ultra-clean transfer of graphene with defect-free is still crucial for large-area graphene devices' efficiency. This review introduces a comprehensive and up-to-date account of the transfer of the most attention kinds of CVD-grown graphene on copper substrates. The advances and main challenges of both wet and dry transfer methods are also carefully described. Particular emphasis is also given on graphene-based BioFET devices, revising their sensing mechanism and the optimum operational conditions toward high specificity and sensitivity. The authors have been convinced that upgrading the transfer process to accomplish the cleanest graphene surface and exploiting the optimum operating conditions will undoubtedly be of considerable significance to fabricate graphene-based devices.