Table 1.
Summary of type of graphene, method of synthesis, method of investigation and the reference.
| S. No. | Type of Graphene | Method of Synthesis | Method of Investigation | Reference |
|---|---|---|---|---|
| 1. | Monolayer to few-layer to multilayer graphene | - | Optical microscopy, Raman spectra | [37] |
| 2. | Monolayer to few-layer to multilayer graphene | - | Optical microscopy, Raman spectra | [40] |
| 3. | Graphite-like thin sheets | - | TEM | [45] |
| 4. | 1–5-layer thick graphene layers | Ultrasonication-induced exfoliation of graphite to graphene in solvent | TEM | [46] |
| 5. | Reduced graphene oxide | Chemical synthesis | XRD, TEM, and other electron spectroscopic methods | [47] |
| 6. | Monolayer graphene | CVD | TEM | [48] |
| 7. | Mono-bilayer graphene | High sulfonic acid edge functionalized graphene from graphite | HR-TEM | [49] |
| 8. | Mono-few-layer graphene | CVD | SEM, Optical, Raman spectra, Raman mapping | [50] |
| 9. | Single or multilayer Graphene flakes | CVD | SEM, Optical, Raman spectra, Raman mapping, and AFM | [51] |
| 10. | Graphene layers stacked 6 to 20 layers thick | Ball milling | SEM, Raman spectra, HRTEM | [52] |
| 11. | Monolayer graphene | CVD | SEM, Optical, microscopy, Raman spectra, Raman mapping, and AFM | [53] |
| 12. | Few-layer graphene | - | SEM, Optical microscopy, HRTEM, Raman mapping, and AFM | [54] |
| 13. | Monolayer graphene | CVD | SEM, Raman spectra, Raman mapping, and AFM. | [55] |
| 14. | Monolayer graphene | Chemical synthesis | AFM | [56] |
| 15. | Few-layer graphene | CVD | AFM | [57] |
| 16. | Graphene flake with thickness in 4–5 nm | - | AFM | [58] |
| 17. | Multilayer graphene | - | AFM | [59] |
| 18. | Monolayer to few-layer graphene | - | AFM | [60] |
| 19. | Monolayer graphene sheet | Liquid phase exfoliation | AFM | [61] |
| 20. | Functionalized reduced graphene | Chemical synthesis | AFM | [62] |
| 21. | Monolayer graphene oxide | Chemical synthesis | Optical microscopy, AFM, SEM | [63] |
| 22. | Mono-bilayer graphene | Chemical synthesis | Optical microcopy | [64] |
| 23. | Mono-few-layer graphene | - | Plasmon exciton coupling spectroscopy | [65] |
| 24. | Graphene flake with 60, 40 and 30 layers thick | - | X-ray diffraction | [66] |
| 25. | Exfoliated graphene sheets | Graphite sonication in solvents | Raman spectra | [70] |
| 26. | Monolayer graphene | CVD | Raman spectra | [71] |
| 27. | Epitaxial graphene | CVD | Raman spectra | [72] |
| 28. | Few-layer graphene | CVD | Raman spectra | [73] |
| 29. | Monolayer to multi-layer graphene | - | Raman spectra | [74] |
| 30. | Multilayer graphene | - | Raman spectra | [75] |
| 31. | Monolayer to few-layer graphene | - | Raman spectra | [76] |
| 32. | Exfoliation in graphene flake | - | Raman spectra | [77] |
| 33. | Monolayer to few-layer graphene | Raman spectra | [78] | |
| 34. | Monolayer to few-layer graphene | Raman spectra | [79] | |
| 35. | Multilayer graphene | CVD | Raman spectra | [80] |
| 36. | Mono to few-layer graphene | Liquid phase exfoliation | Raman spectra | [81] |
| 37. | Monolayer graphene | CVD | Raman mapping | [82] |
| 38. | Graphene flake | CVD | Raman mapping | [83] |
| 39. | 3D graphene films | CVD | Raman mapping | [84] |
| 40. | Bilayer graphene | CVD | Raman mapping | [85] |
| 41. | Graphene flake | - | Raman mapping | [86] |
| 42. | Graphene flake | CVD | Raman mapping | [87] |
| 43. | Monolayer graphene | - | Raman mapping | [88] |
| 44. | Mono-bilayer graphene | CVD | Raman mapping | [89] |
| 45. | Mono-bilayer graphene | - | Raman mapping | [90] |
| 46. | Mono-few-layer graphene | - | Spin hall effect, Raman spectra | [91] |
| 47. | Mono-bilayer graphene | - | Scanning tunneling microscopy | [92] |
| 48. | Mono-few–multilayer graphene | - | Scanning electrochemical microscopy and AFM | [93] |