Activating photosensitivity in polycrystalline PbSe via in-situ oxygen ion beam induction

An in situ O+ beam method for preparing mid-infrared sensitive polycrystalline lead selenide thin films has been demonstrated. By interaction with low energy ion beam, the optical band gap of the material can be adjusted to the extent that it is more suitable for absorption and detection of mid-infrared photons. The structural properties and the Urbach energy as low as 1.1 meV both suggest a well-ordered microstructure with high crystallinity. The preliminary optoelectronic measurements suggest its mid-IR sensitivity and a comparable responsivity of 0.62 A/W at 3.0 mu m. Unlike the traditional thermal diffusion, this method therefore provides a rapid material sensitization and only requires a low temperature annealing without oxygen or iodine. This method may provide a new low-cost and easy-processing approach to fabricate mid-IR photosensitive lead chalcogenides.