(February 1, 2016) EPFL scientists build the most sensitive
carbon nanotube-based photodetector to date. The material is sensitized with
CN3NH3PbI3 perovskite nanowires, which propel its responsivity by almost seven
orders of magnitude.
Semiconducting carbon nanotubes are often used in
photovoltaic and optoelectronic devices. But light detection with pristine
carbon-nanotube field-effect phototransistors so far is limited in the range of
10% quantum efficiency. The responsivity of the best carbon nanotube devices is
around 0.1 A/W. Publishing in Nanoscale, EPFL scientists have now fabricated a
carbon-nanotube photodetector with responsivity as high as 7.7×105 A/W.
The lab of László Forró, led by postdocs Bálint Náfrádi and
Endre Horváth, at EPFL built the device and overlaid it with perovskite
(CN3NH3PbI3) nanowires to sensitize its light-detection capacity. The
unprecedented high performance is a result of the two materials working
together: the perovskite nanowires can convert incoming light into free
charge-carriers with high efficiency, while the carbon nanotube transfers the
electrons to the detection circuit.