Wang S, Sekine Y, Suzuki S, Maeda F, Hibino H
NTT Basic Research Laboratories, NTT Corporation, Atsugi, Kanagawa 243-0198, Japan.
Nanotechnology. 2015 Sep 25;26(38):385203. doi: 10.1088/0957-4484/26/38/385203. Epub 2015 Sep 3.
A back-gate graphene p-n junction was achieved by selective interfacial modification of a chemical vapor deposition (CVD)-grown graphene field effect transistor (FET). Silane self-assembled monolayer (SAM) patterns were used to fabricate uniform p- and n-doped regions and a sharp p-n junction in the graphene FET channel. A gate-dependent photocurrent response was observed at the graphene p-n junction, and exhibited a maximum signal between two Dirac point voltages of SAM-doped graphene regions. A spatial photocurrent map shows that the photocurrent generated at the junction region was much larger than that from graphene/electrode junctions under the same incident laser power. This single-peak characteristic photocurrent in CVD graphene is dominated by the photothermoelectric contribution, and is highly sensitive to the power of incident laser. The SAM interfacial modification method provides a feasible route for the fabrication of efficient graphene-based photodetectors.
通过对化学气相沉积（CVD）生长的石墨烯场效应晶体管（FET）进行选择性界面修饰，实现了背栅石墨烯p-n结。硅烷自组装单层（SAM）图案用于在石墨烯FET沟道中制造均匀的p型和n型掺杂区域以及尖锐的p-n结。在石墨烯p-n结处观察到了与栅极相关的光电流响应，并且在SAM掺杂的石墨烯区域的两个狄拉克点电压之间表现出最大信号。空间光电流图表明，在相同入射激光功率下，结区域产生的光电流远大于石墨烯/电极结产生的光电流。CVD石墨烯中的这种单峰特征光电流由光热电贡献主导，并且对入射激光的功率高度敏感。SAM界面修饰方法为制造高效的基于石墨烯的光电探测器提供了一条可行的途径。
