Probing photoresponse of aligned single-walled carbon nanotube doped ultrathin MoS.

We report a facile method to produce ultrathin molybdenum disulfide (MoS) hybrids with polarized near-infrared (NIR) photoresponses, in which horizontally-aligned single-walled carbon nanotubes (SWNTs) are integrated with single- and few-layer MoS through a two-step chemical vapor deposition process. The photocurrent generation mechanisms in SWNT-MoS hybrids are systematically investigated through wavelength- and polarization-dependent scanning photocurrent measurements. When the incident photon energy is above the direct bandgap of MoS, isotropic photocurrent signals are observed, which can be primarily attributed to the direct bandgap transition in MoS. In contrast, if the incident photon energy in the NIR region is below the direct bandgap of MoS, the maximum photocurrent response occurs when the incident light is polarized in the direction along the SWNTs, indicating that photocurrent signals mainly result from the anisotropic absorption of SWNTs. More importantly, these two-dimensional (2D) hybrid structures inherit the electrical transport properties from MoS, displaying n-type characteristics at a zero gate voltage. These fundamental studies provide a new way to produce ultrathin MoS hybrids with inherited electrical properties and polarized NIR photoresponses, opening doors for engineering various 2D hybrid materials for future broadband optoelectronic applications.