LAUSR

Abstract Photoconductive thin films on the basis of PbSe have been used as functional materials for infrared (IR) detectors. High quality PbSe thin films were grown on glass substrates by chemical bath deposition (CBD) yielding a peak detectivity of 2.8 × 10 10  cm Hz 1/2  W −1  at room temperature. The photoconductive sensor function is established by a sensitization process by annealing PbSe films in oxygen and iodine rich atmospheres. By studying such sensitized PbSe layers we discovered that new, quaternary phases are formed at the top of the layered structure. We could show that after annealing the following layer structure had formed: a bottom layer of PbSe (1 μm) and a top layer of Pb-Se-O-I (400 nm), containing (i) a poly-crystalline and (ii) a nano-crystalline phase. The poly-crystalline phase was found to be a solid solution of Se and I and yielded an average Pb/I mole fraction ratio of 3.1 and Pb/Se of 3.9, respectively. It contained the largest iodine mole fraction of ∼20 at.% while the nano-crystalline phase yielded less iodine (