Flexible phototransistors based on graphene nanoribbon decorated with MoS2 nanoparticles

• Photo-transistors based on graphene nanoribbon decorated with MoS2 NPs have been demonstrated.
• Photo-responsivity of 66 A W−1 obtained which is much higher than the first reported pristine device.
• Rise-time and decay-time of 5 ms and 30 ms, respectively, have been obtained.
• Photogenerated trapped holes in the NPs induced photo-gating effect.
• Fabricated devices show a high stability for bending radii larger than 6 mm.

This paper presents highly efficient, flexible, and low-cost photo-transistors based on graphene nanoribbon (GNR) decorated with MoS2 nanoparticles (NPs). Due to high carrier mobility, GNR has been used as carrier transport channel and MoS2 NPs provide strong advantage of high gain absorption and the generation of electron-hole pairs. These pairs get separated at the interface between GNR and MoS2 NPs, which leads to electron transfer from NPs towards GNR. The fabricated devices based on GNR-MoS2 hybrid material show a high photo-responsivity of 66 A W−1 and fast rise-time (tr) and decay-time (td) of 5 ms and 30 ms, respectively, under blue laser illumination with a wavelength of 385 nm and power density of 2.1 μW. The achieved photo-responsivity is 1.3×105 and 104 times larger than that of the first reported pristine graphene and MoS2 photo-transistors, respectively. Furthermore, fabricated devices show a high stability for bending radii larger than 6 mm. The simple solution based process, high gain and reproducible operation of fabricated photo-transistors indicate potential applications of them in state of the art photo-detectors and imaging systems.