摘要： Single-crystalline Ge nanowires have been synthesized on Au-coated Si substrates through a thermal evaporation, condensation method and vapor-liquid-solid mechanism. The [111] growth direction of the Ge nanowires was analyzed using HRTEM and fast Fourier transform diffraction patterns. Global back-gated Ge nanowire field-effect transistors (FETs) on the Si 3 N 4 dielectrics were fabricated and studied, showing p-type behavior and a field effect hole mobility of 44.3 cm 2 V −1 s −1 . The Ge channel length could be well controlled through the annealing process. After a rapid thermal annealing (RTA) process, Ni 2 Ge/Ge/Ni 2 Ge nano-heterostructures were formed. The electrical transport properties were effectively improved by the heterojunction rather than the metal contact. The epitaxial relationship between Ge and orthorhombic Ni 2 Ge was Ge[110]//Ni 2 Ge[110] and Ge(-11-1)//Ni 2 Ge(1-1-2). From electrical transport properties, the measured resistivity of the Ge nanowires was much lower than intrinsic bulk Ge material. A room temperature photoluminescence spectrum of the Ge nanowires possessed a broad blue emission with a peak at 462 nm in wavelength, which was attributed to the oxide-related defect states. Due to the existence of the defects, a Ge nanowire FET was able to detect visible light and serve as a nanowire photodetector. The growth and electrical transport properties of single-crystalline Ge nanowires and germanide/Ge nano-heterostructures are discussed. Due to the existence of defects, a Ge nanowire field-effect transistor was able to serve as a photodetector. 出版日期： 2011-12-05 資源來源： Royal Society of Chemistry 識別號： EISSN: 1466-8033 識別號： DOI: 10.1039/c1ce06107k
