The magnetic,electronic,and optical properties of transition metal X(X=Cr,Mn,Fe,Tc,Re)a-tomically doped Janus Ga2SSe are investigated using the first-principles plane-wave method based on the den-sity functional theory.It's shown that the transition metal-doped Janus Ga2SSe systems have better stability un-der Chalcogen-rich condition than under Ga-rich condition.The Mn-doped system has the lowest formation energy under both conditions.The intrinsic Ga2SSe is an indirect bandgap semiconductor with a bandgap of 2.02 eV and has good photovoltaic absorption in the ultraviolet(UV)region.Compared with the intrinsic Ga2SSe,the impurity energy levels appear in the spin-up channel of the Cr-doped system,which makes the spin-up and spin-down channels asymmetric,and presents the ferromagnetic semimetal property with a magnetic moment of 2.797 μB.The impurity energy levels appear in the spin-up channel of the Mn-doped system,making the system become a magnetic P-type semiconductor with a magnetic moment of 3.645 µB.The impurity energy level appears in the spin-down channel of the Fe-doped system,making the system become a magnetic P-type semiconductor with a magnetic moment of 3.748 μB magnetic.After doping of Tc and Re,the band gaps are changed from indirect to direct band gaps,and both systems are non-magnetic P-type semiconductors.In terms of optical properties,each doped system has significantly enhanced dielectric constant and refractive coeffi-cient compared with undoped Ga2SSe,and the absorption coefficient appears blue-shifted in the high energy re-gion(3-10 eV).It has potential applications in the field of UV detectors and photovoltaic absorption.
关键词
二维Janus/Ga2SSe/过渡金属掺杂/磁学性质/电子结构/光学性质
Key words
Two-dimensional Janus Ga2SSe/Transition metal doping/Magnetic properties/Electronic struc-ture/Optical properties
万方数据