The
growth of high-quality two-dimensional (2D) layered chalcogenide crystals
is highly important for practical applications in future electronics,
optoelectronics, and photonics. Current route for the synthesis of
2D chalcogenide crystals by vapor deposition method mainly involves
an energy intensive high-temperature growth process on solid substrates,
often suffering from inhomogeneous nucleation density and grain size
distribution. Here, we first demonstrate a facile vapor-phase synthesis
of large-area high-quality 2D layered chalcogenide crystals on liquid
metal surface with relatively low surface energy at a growth temperature
as low as ∼100 °C. Uniform and large-domain-sized 2D crystals
of GaSe and GaxIn1–xSe were grown on liquid metal surface even supported
on a polyimide film. As-grown 2D GaSe crystals have been fabricated
to flexible photodetectors, showing high photoresponse and excellent
flexibility. Our strategy of energy-sustainable low-temperature growth
on liquid metal surface may open a route to the synthesis of high-quality
2D crystals of Ga-, In-, Bi-, Hg-, Pb-, or Sn-based chalcogenides
and halides.