Ge掺杂对InI导电性能影响的第一性原理研究

First-principles study on the effect of Ge-doping on the conductivity of In I

采用密度泛函理论框架下的第一性原理平面波超软赝势方法,在相同环境条件下对不同浓度Ge掺杂的In I导电性能进行了研究.建立了由不同浓度的Ge原子替代In原子的In1-x Ge x I(x=0,0.125,0.25)模型.对低温下高掺杂Ge原子的In1-x Ge x I半导体的优化参数、总态密度、能带结构进行了计算.结果表明:Ge的掺入使In1-x Ge x I材料的体积减小,总能量升高,稳定性降低;Ge原子浓度越大,进入导带的相对电子数量越多,In1-x Ge x I电子迁移率减小,电阻率增大,同时最小光学带隙也增大,有利于改善体系的核探测性能.

The conductivities of In I with different concentrations of Ge-doping have been investigated by the ultra-soft pseudopotential approach of the plane-wave based on the density functional theory under the same condition. Models of the In1-xGexI（x = 0, 0.125, 0.25） with In atoms substituted by different fraction of Ge are set up. The optimized structural parameters, total electron density of states, and energy band structures of Ge heavily doped In1-xGexI semiconductors at low temperature are calculated. Results show that the volumes are slightly reduced and the total energies are increased in the In1-xGexI systems and that the systems become instable. As the concentration of Ge increases, the electronic mobility decreases, but the relative number of electrons jumping to the conduction band increases, and the resistivity and the minimum optical band gap increase at the same time, which is beneficial to improving the performance of nuclear detection in the system.