Laser-induced surface recrystallization of polycrystalline PbI2 thick films for X-ray detector application

Abstract In this work, laser-induced surface recrystallization process was developed to improve the surface properties and device performance of the polycrystalline PbI 2 thick films prepared by using close space vapor deposition method. A continuous polycrystalline PbI 2 recrystallized layer with a better mechanical strength and reflectivity improved from 2% to 4%–6% was obtained by this recrystallization process for the films with mechanical pretreatment. Other polytypes is absent in the recrystallized layer with the 2H-polytype remaining before and after treatment and obtaining improved electrical and X-ray photoelectric response performance. The pretreatment such as mechanical cutting/polishing and hydrogenation is necessary to lower the non-wetting crystallization behavior during the recrystallization process due to the rough surface state and oxygen contamination.