First Principle Study On The Electronic And Optical Properties Of Indium Iodide With Tl、Ge Single-Doped

Detectors that work with the chips made by Indium Iodide crystals have high energy resolution and high detective efficiency for γ-ray. The detector made by In I crystals can be used and stored in room temperature, which make In I one of the key new materials for room temperature nuclear radiation detectors. In the early time, researchers were focused on improving the preparation technology of indium iodide crystal to achieve the purpose of improving its nuclear detection performance, but the results were not so satisfactory. At the same time, to improve the performance of the semiconductor by doping, some elements has been widely used in other semiconductor materials. Based on the background above, in this paper, the properties of pure In I and Tl、Ge doped In I were calculated and deeply studied by the software of Materials Studio which is based on first-principles calculations. And focused on the effect on electronic structure and optical properties of Tl、Ge doped In I.Firstly, models for pure In I are set up,the structures such as band gap, density of states and optical properties like dielectric function, absorption of pure In I were calculated by Materials Studio. The physical properties of pure In I were obtained.Secondly, supercell models for different concentrations of Tl-doped In I were set up, and the geometry optimizations for the models were carried out. The total density of states, the band structures and the optical properties were also calculated. The reasons of the decrease of the formation energy, the increase of the band gap and the blue shift of the absorption spectrum after doping were analyzed in depth.Finally, supercell models with In atoms substituted by different concentration of Ge are set up. The lattice parameters, total electron density of states and energy band structures of Ge heavily doped In I semiconductors at low temperature were calculated. The influence of different doping concentration of Ge atoms on the conductivity of In I was analyzed in the same environment; the reason why the electrical resistivity and the optical band gap increase with the increase of the concentration of Ge atoms was explained accordingly.