  We report on the fabrication and characterization of synthesized multiwall
MoS2 nanotube (NT) and nanoribbon (NR) field-effect transistors (FETs). The
MoS2 NTs and NRs were grown by chemical transport, using iodine as a transport
agent. Raman spectroscopy confirms the material as unambiguously MoS2 in NT,
NR, and flake forms. Transmission electron microscopy was used to observe cross
sections of the devices after electrical measurements and these were used in
the interpretation of the electrical measurements allowing estimation of the
current density. The NT and NR FETs demonstrate n-type behavior, with ON/OFF
current ratios exceeding 10^3, and with current densities of 1.02
{\mu}A/{\mu}m, and 0.79 {\mu}A/{\mu}m at VDS = 0.3 V and VBG = 1 V,
respectively. Photocurrent measurements conducted on a MoS2 NT FET, revealed
short-circuit photocurrent of tens of nanoamps under an excitation optical
power of 78 {\mu}W and 488 nm wavelength, which corresponds to a responsivity
of 460 {\mu}A/W. A long channel transistor model was used to model the
common-source characteristics of MoS2 NT and NR FETs and was shown to be
consistent with the measured data.
