  Organolead trihalide perovskites have drawn substantial interest for
applications in photovoltaic and optoelectronic devices due to their low
processing cost and remarkable physical properties. However, perovskite thin
films still suffer from low carrier mobility, limiting their device performance
and application potential. Here we report that embedding single-walled carbon
nanotubes into halide perovskite films can significantly enhance the hole and
electron mobilities to record-high values of 595.3 and 108.7 cm2 V-1 s-1,
respectively. In the ambipolar phototransistors with such hybrid channels,
photo-carriers generated in the light-absorbing perovskite matrix are
transported by the carbon nanotubes, leading to ultrahigh detectivity of 6 *
1014 Jones and responsivity of 1 * 104 A W-1. We find that the perovskite
precursor in dimethylformamide solution serve as an excellent stabilizer for
the dispersion of carbon nanotubes, which potentially extend the scope of
applications of perovskites in solution-processed functional composites. The
unprecedented high performances underscore the perovskite/carbon nanotubes
hybrids as an emerging class of functional materials in optoelectronic and
other applications.
