Surface transfer doping induced effective modulation on ambipolar characteristics of few-layer black phosphorus

Du Xiang, Cheng Han, Jing Wu, Shu Zhong, Yiyang Liu, Jiadan Lin, Xue-Ao Zhang, Wen Ping Hu, Barbaros Özyilmaz, A. H. Castro Neto, Andrew Thye Shen Wee, Wei Chen
2015 Nature Communications  
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 (Cs 2 CO 3 ) and molybdenum trioxide (MoO 3 ), respectively. Cs 2 CO 3 is found to strongly electron dope black phosphorus. The electron mobility of black
more » ... n mobility of black phosphorus is significantly enhanced to B27 cm 2 V À 1 s À 1 after 10 nm Cs 2 CO 3 modification, indicating a greatly improved electrontransport behaviour. In contrast, MoO 3 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.
doi:10.1038/ncomms7485 pmid:25761440 fatcat:ggf5d6vbebcitp73hdjgjftsmq