Se与Te替位掺杂对WS_(2)-MoS_(2)纳米器件电子输运性质的影响

Effect of Se and Te Substitution Doping on Electronic Transport Properties of WS_(2)-MoS_(2)Nanodevices

基于密度泛函理论与非平衡格林函数相结合的第一性原理计算方法,研究了Se与Te原子替位掺杂对WS_(2)-MoS_(2)纳米器件电子输运性质的影响.结果表明,WS_(2)-MoS_(2)纳米器件为间接带隙半导体,器件电流在[+0.7 V,+1.0 V]与[-1.0 V,-0.9 V]偏压范围内随着偏压的增大逐渐减小,呈现显著的负微分电阻效应;Se与Te原子对WS_(2)-MoS_(2)纳米器件进行替位掺杂后均呈现有趣的负微分电阻效应,器件两端电流的隧穿也显著改善;Se原子对WS_(2)-MoS_(2)纳米器件中S原子进行替位掺杂时,器件转化为p型半导体;Te原子对WS_(2)-MoS_(2)纳米器件中S原子进行替位掺杂时,器件转化为p型半导体甚至金属,且导电性能大幅提升.

Based on the first-principles calculation method of combining the density functional theory and the Non-equilibrium Green's function,the effect of Se and Te atom substitution doping on the electronic transport properties of WS_(2)-MoS_(2)nanodevice is studied.The results show that the WS_(2)-MoS_(2)nanodevice has interesting negative differential resistance effect in the bias range of[+0.7 V,+1.0 V]and[-1 V,-0.9 V],with the current gradually decreasing with the increase of bias voltage,and the electronic transport properties of the device show indirect gap semiconductor characteristics.The device can be converted into p-type semiconductor when replaing the S-atoms in WS_(2)-MoS_(2)composite nanodevice with Se-atoms.When the S-atoms in WS_(2)-MoS_(2)composite nanodevice is partially doped with substitutional Te-atoms,the device is converted into p-type semiconductor or even metal,and its conductivity is greatly improved.The partial substitution doping of WS_(2)-MoS_(2)nanodevice with Se and Te atoms exhibits a negative differential resistance effect,and the passing of currents across the devices is significantly improved.