Photoresponse and field-emission properties of bismuth sulfide nanoflowers

Elegant 61283 nanoflowers were prepared via a simple vapor deposition process. Compared to the Bi₂S₃ nanorods bundles, the conductivity of the nanoflowers is much more sensitive to simulated sunlight exposure. The light-induced conductivity increase allows us to reversibly switch the nanoflowers between "OFF" and "ON" states, an optical gating phenomenon analogous to the commonly used electrical gating, which show the possibility of creating highly sensitive photodetectors and optical switches using these Bi₂S₃ nanoflowers. Moreover, the field emission measurements confirm that the present nanoflowers are excellent field emitters with the turn-on field of 7.45 eV. Therefore, these Bi ₂S₃ nanoflowers with large proportion of free open edges may be attractive in novel nanoscale electric and optoelectronic devices.