A nano-structured PbSe polycrystalline material prepared by ion beam implantation: Properties and comparison with the diffusion counterpart

Manipulating the stoichiometric distribution along depth direction is a promising technique to modulate the optical and optoelectronic properties of the mid-infrared sensitive lead chalcogenides at room temperature. Here, we demonstrate an optoelectronic sensitization method based on O⁺ beam implantation at 50 kV for polycrystalline PbSe, which can manipulate the depth profile and hence the structural properties to modulate the optical and the optoelectronic performances. Unlike the diffused material presented in previous works, the resulting material is nano-polycrystalline with average grain sizes of 17.1–29.3 nm. The optoelectronic characterizations indicate that the optoelectronic properties can indeed be modulated by the implantation dose. The responsivity up to 2.09 A/W at 4 μm has been obtained at room temperature from the sample with implantation dose of 1 × 10¹⁸ cm⁻². Comparing with the diffusion counterpart, the ion prepared PbSe nanomaterial exhibits completely different structural, compositional, optical, and electrical properties. The high responsivity of this material is attributed to the high optical absorption and carrier mobility induced by O⁺ beam. However, the high dark current has been also observed in this material, mainly due to its low inherent potential barrier height between crystallites.