Issue
Korean Chemical Engineering Research,
Vol.49, No.3, 297-300, 2011
고에너지 양성자에 의해 결함을 증가시킨 그래핀 소자의 전기적 특성 변화 연구
High-energy Proton Irradiated Few Layer Graphene Devices
Mechanical exfoliation 방법에 의해 제작된 그래핀(Few Layer Graphene: FLG) 소자에 양성자를 조사하여 의도적으로 결함의 수를 증가시켰다. 그 후 공기중에 노출되었을 때와 진공상태에서 보관한 후에 측정된 전기적 특성을 확인하였다. 또한 UV에 노출시킨 후와 진공상태에서 열처리를 진행한 후에 전기적 특성의 변화들을 관찰하였다. 진공상태에서 보관한 그래핀 소자는 표면에 흡착되어 도펀트로 작용하게되는 species의 수가 감소하기 때문에 전류가 감소하는 결과를 나타내었다. UV에 노출된 상태에서는 오존에 의한 영향으로 약간의 전류 상승이 일어나지만 케리어의 이동도가 감소하게 된다. 반면 진공상태에서 열처리 후에는 전류는 매우 감소하게 되지만 결함과 도펀트에 의한 케리어 산란 현상이 감소하게 되므로 이동도는 크게 증가하게 된다.
High energy proton irradiations were performed on graphene devices to increase the number of defects intentionally. Proton energy and fluence were 6 MeV and 5×1015 cm^(-2), respectively. The defects in few layer graphene layer created by proton irradiations captured oxygen molecules that acted as p-type dopants. After the vacuum annealing, hole mobility was enhanced by the recovery of the defects and the desorption of the oxygen molecules. However, the drain current decreased after vacuum annealing due to the removal of the dopant molecules.
[References]
  1. Lee C, Wei X, Kysar JW, Hone J, Science., “Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene", 321, 385, 2008
  2. Balandin AA, Ghosh S, Bao W, Calizo I, Teweldebrhan D, Miao F, Lau CN, Nano. Lett., “Superior Thermal Conductivity of Single-layer Graphene", 8, 902, 2008
  3. Berger C, Song Z, Li X, Wu X, Brown N, Naud C, Mayou D, Li T, Hass J, Marchenkov AN, Conrad EH, First PN, Heer WA, Science., “Electronic Confinement and Coherence in Patterned Epitaxial Graphene", 312, 1191, 2006
  4. Novoselov KS, Geim AK, Morozov SV, Jiang D, Zhang Y, Dubonos SV, Grigorieva IV, Firsov AA, Science., “Electric Field Effect in Atomically Thin Carbon Films", 306, 666, 2004
  5. Eda G, Fanchini G, Chhowalla M, Nat. Nanotechnol., “Large-area Ultrathin Films of Reduced Graphene Oxide as a Transparent and Flexible Electronic Material", 3, 270, 2008
  6. Wang X, Zhi L, Mullen L, Nano. Lett., “Transparent, Conductive Graphene Electrodes for Dye-sensitized Solar Cells", 8, 323, 2008
  7. Hummers WS, Offeman JRE, J. Am. Chem. Soc., “Preparation of Graphitic Oxide”, 80, 1339, 1958
  8. Gu G, Nie S, Feenstra RM, Devaty RP, Choyke WJ, Chan WK, Kane MG, Appl. Phys. Lett., “Field Effect in Epitaxial Graphene on a Silicon Carbide Substrate", 90, 253507, 2007
  9. Reina A, Jia X, Ho J, Nezich D, Son H, Bulovic V, Dresselhaus M, Kong J, Nano.Lett., “Large Area, Few-Layer Graphene Films on Arbitrary Substrates by Chemical Vapor Deposition", 9, 30, 2009
  10. Kim KS, Zhao Y, Jang H, Lee SY, Kim JM, Kim KS, Ahn JH, Kim P, Choi JY, Hong BH, Nature., “Large-scale Pattern Growth of Graphene Films for Stretchable Transparent Electrodes", 457, 706, 2009
  11. Zhang YH, Chen YB, Zhou KG, Liu CH, Zeng J, Zhang HL, Peng Y, Nanotechnology., “Improving Gas Sensing Properties of Graphene by Introducing Dopants and Defects: a First-principles Study", 20, 185504, 2009
  12. Claeys C, Simoen E., “Radiation Effects in Advanced Semiconductor Materials and Devices,” Springer, Berlin, 2002
  13. Compagnini G, Giannazzob F, Sonde S, Raineri V, Rimini E, Carbon., “Ion Irradiation and Defect Formation in Single Layer Graphene”, 47, 3201, 2009
  14. Teweldebrhan D, Balandin AA, Appl. Phys. Lett., “Modification of Graphene Properties Due to Electron-beam Irradiation", 94, 013101, 2009
  15. Kim K, Choi J, Lee H, Lee HK, Kang TH, Han YH, Lee BC, Kim S, Kim B, J.Phys. Chem. C., “Effects of 1 MeV Electron Beam Irradiation on Multilayer Graphene Grown on 6H-SiC(0001)”, 112, 13062, 2008
  16. Ko G, Kim HY, Ren F, Pearton SJ, Kim J, Electrochem. Solid State Lett., “Electrical Characterization of 5MeV Proton-Irradiated Few Layer Graphene”, 13(4), K32, 2010