C₆₀ Functionalized Single‐Walled Carbon Nanotube‐based Phototransistor for Efficient Detection of Visible Light Under Appropriate Gate Electrostatics

Abstract The current study concerns highly reliable visible light sensing by C 60 fullerene functionalized single‐walled carbon nanotube (SWCNT) based phototransistor. The absorbance of visible light (532 nm) increases significantly due to the formation of an interlink between the SWCNT network and C 60 clusters. Photogenerated excess electrons in SWCNT are trapped by the C 60 clusters and increase the effective hole concentrations in the SWCNT channel, which eventually improves the photoconductive gain. C 60 ‐SWCNT channel is further integrated into the back gated field effect transistor (FET) structure in which 90 nm SiO 2 dielectric thickness is used. The responsivity toward visible light is further enlarged with appropriate negative gate electrostatic. In order to ensure the morphological and structural behavior of C 60 ‐SWCNT, various microscopic and spectroscopic characterizations are performed. The C 60 ‐SWCNT phototransistor exhibits responsivity of 1.219 A W −1 at V gs = – 21 V. The detectivity and rise/fall time of C 60 ‐SWCNT came around to be 2.34 × 10 10 Jones, 86.42 ms/3.35 ms at the same V gs . The maximum external quantum efficiency (EQE) of the C 60 ‐SWCNT phototransistor is very high, ≈274%. In the overall study, a comprehensive discussion is introduced on the effect of variable gate potential on the performance of the C 60 ‐SWCNT phototransistor.