Single-crystalline Bi2S3 nanowire network film and its optical switches

A single-crystalline bismuth sulfide (Bi2S3) nanowire network film at a centimeter scale is fabricated by the facile hydrothermal method. The Bi2S3 film is easily tape-transferred onto a soft plastic substrate, and is further used to fabricate optical switches by screen-printing an Ag electrode array on its top. Our studies demonstrate that the Bi2S3 nanowire network has a pronounced increase in conductance upon exposure to visible light, and possesses a very fast response time of about 2 ms. This work provides a simple and economic method to fabricate a high performance optical switch array and could offer great potential for a low cost, mass-manufacturing process.