Large-sized PbI2 single crystal grown by co-solvent method for visible-light photo-detector application

In this work, we used a simple co-solvent method to prepare large-sized freestanding PbI2 single crystals by heating the solution. The obtained hexagonal slabs were confirmed as 2H-type PbI2 single crystals with a band gap of 2.3 eV. Photo-detector employing such single crystal Was demonstrated to show promising performances to 450 nm laser including great photo-switch current ratio (104), promotable responsivity (0.18 AW(-1)), external quantum efficiency (49.6%), specific detectivity (3.23 x 1011 Jones) and fast (rise time of 323 mu s and decay time of 520 mu s), stable, switchable photo-response. These results substantiate the PbI2 single crystals synthesized by such co-solvent method as promising candidates for optoelectronic applications. (C) 2017 Elsevier B.V. All rights reserved.