直接带隙半导体In_(2)(PS_(3))_(3)单层结构与电子特性的第一性原理研究

First-principles study on structure and properties of In_(2)(PS_(3))_(3)monolayer with a direct band-gap

高载流子迁移率和可调直接带隙是低维电子器件应用的两个关键特性.但目前发现的此类二维材料稀少.鉴于此在第一性原理计算的基础上,本文系统研究了In_(2)(PS_(3))_(3)单层的稳定性、电子结构性质和机械性质.研究结果表明,In_(2)(PS_(3))_(3)单层是具有直接带隙的半导体材料(1.58 eV).在-3%到3%应变下,In_(2)(PS_(3))_(3)单层的带隙是可以调节的(1.3~1.8 eV).声子谱、分子动力学和弹性常数的计算结果表明,In_(2)(PS_(3))_(3)单层是热力学、动力学和机械稳定的.此外,In_(2)(PS_(3))_(3)单层的剥离能(0.21 J m^(-2))小于石墨烯的剥离能(0.36 J m^(-2)),有望像石墨烯一样机械剥离得到.这些优异的的性能使得In_(2)(PS_(3))_(3)单层有望成为未来纳米光电子设备的候选材料之一.

High carrier mobility and moderate band gap are two key properties of electronic device applications.A new two-dimensional semiconductor,namely,In_(2)(PS_(3))_(3)monolayer,with novel electronic properties,is predicted based on first-principles calculations.The results shows that In_(2)(PS_(3))_(3)monolayer possess a direct band gap(1.58 eV),which can be manipulated under uniaxial and biaxial strains(1.3~1.8 eV).In addition,the stripping energy of In_(2)(PS_(3))_(3)monolayer(0.21 jm^(-2))is less than that of graphene(0.36 jm^(-2)),which is expected to be obtained by mechanical stripping like graphene.The exceptional properties render In_(2)(PS_(3))_(3)monolayer a promising candidate in future high-speed optoelectronic devices.