1] Department of Physics, National University of Singapore, Singapore 117542, Singapore [2] Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore.
1] Department of Physics, National University of Singapore, Singapore 117542, Singapore [2] Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore [3] NanoCore, National University of Singapore, Singapore 117576, Singapore.
Nat Commun. 2015 Mar 12;6:6485. doi: 10.1038/ncomms7485.
Black phosphorus, a fast emerging two-dimensional material, has been configured as field effect transistors, showing a hole-transport-dominated ambipolar characteristic. Here we report an effective modulation on ambipolar characteristics of few-layer black phosphorus transistors through in situ surface functionalization with caesium carbonate (Cs2CO3) and molybdenum trioxide (MoO3), respectively. Cs2CO3 is found to strongly electron dope black phosphorus. The electron mobility of black phosphorus is significantly enhanced to ~27 cm(2) V(-1) s(-1) after 10 nm Cs2CO3 modification, indicating a greatly improved electron-transport behaviour. In contrast, MoO3 decoration demonstrates a giant hole-doping effect. In situ photoelectron spectroscopy characterization reveals significant surface charge transfer occurring at the dopants/black phosphorus interfaces. Moreover, the surface-doped black phosphorus devices exhibit a largely enhanced photodetection behaviour. Our findings coupled with the tunable nature of the surface transfer doping scheme ensure black phosphorus as a promising candidate for further complementary logic electronics.
黑磷，一种新兴的二维材料，已被配置为场效应晶体管，表现出空穴传输主导的双极性特性。在这里，我们通过原位表面功能化分别用碳酸铯（Cs2CO3）和三氧化钼（MoO3）来报告对少层黑磷晶体管的双极性特性的有效调制。结果发现，Cs2CO3 强烈地电子掺杂黑磷。在 10nm Cs2CO3 修饰后，黑磷的电子迁移率显著提高到约 27cm2V-1s-1，表明电子输运性能得到了极大的改善。相比之下，MoO3 的修饰则表现出巨大的空穴掺杂效应。原位光电子能谱表征表明，在掺杂剂/黑磷界面处发生了显著的表面电荷转移。此外，表面掺杂的黑磷器件表现出大大增强的光电探测性能。我们的研究结果以及表面转移掺杂方案的可调性质，确保了黑磷作为进一步互补逻辑电子学的有前途的候选材料。
