  The field effect transistors (FETs) exhibited ultrahigh responsivity (107
A/W) to infrared light with great improvement of mobility in graphene / PbS
quantum dot (QD) hybrid. These reported transistors are either unipolar or
depletion mode devices. In this paper, we presented and fabricated
conveniently-controlled grapheme / PbS QD hybrid FETs. Through the
investigation on electric and optoelectronic properties, the ambipolar FETs
(normally OFF) can be switched ON by raising gate voltage (VG) up to 3.7 V and
-0.8 V in the first and third quadrants. Near these thresholds (VT) each
carrier species shows comparable mobility (~ 300 cm2V-1s-1). Photo-responsivity
reach ~ 107 A/W near each threshold and it will linearly increases with
(VG-VT). These hybrid FETs become strongly competitive candidates for devices
in flexible integrated circuits with low cost, large area, low-energy
consumption and high performances.
