Nature of radiative recombination processes in layered semiconductor PbCdI2 nanostructural scintillation material

We report on the efficient photoluminescence (PL) and radioluminescence (RL) of the PbI2 nanoclusters (NCLs), which are naturally formed in the nanostructured Pb1-XCdxI2 alloys (X=0.70). Here, we carried out the studies of the nature of radiative recombination processes in the NCLs of various sizes by measuring PL temperature evolution. Our results indicate that at low temperatures the PL is mainly caused by exciton emission and recombination of donor-acceptor pairs, generated in volume of large NCLs. The broad bands, which are associated with the deep intrinsic surface states, including self-trapped excitons (STEs), are dominant in the PL spectra at higher temperature (>100 K). Our work shows that the nature of emission, associated with RL bands is analogous to that for PL bands. It was shown that the investigated nanostructured material is strongly radiation-resistant. Thus, the Pb1-XCdXI2 alloys can be considered as new effective layered semiconductor nanostructured materials which can be suitable for the elaboration of perspective semiconductor scintillators. These nanomaterials have promising prospects for applications in new generations of devices for biomedical diagnostics and industrial imaging applications.