摘要
采用第一性原理计算方法研究了MoSi_(2)N_(4)/GeC异质结,对其进行结构、电子及光学特性的计算,并探究施加不同双轴应变和垂直电场对异质结能带结构及光吸收特性的影响,研究表明:MoSi_(2)N_(4)/GeC异质结是一种带隙为1.25 eV的间接带隙半导体,具有由GeC层指向MoSi_(2)N_(4)层的内建电场.此外,其光生载流子转移机制符合S型异质结机理,从而提高了光催化水分解的氧化还原电位,使其满足pH=0—14范围内的光催化水分解要求.双轴应变下,带隙随压缩应变的增加而先增大再减小,且在紫外区域的光吸收性能随压缩应变的增加而增强.带隙随拉伸应变的增大而减小,且可见光区域的光吸收性能较压缩应变时增强.垂直电场下,带隙随正电场的的增加而增大,随负电场的增大而减小.综上,MoSi_(2)N_(4)/GeC异质结可以作为一种高效的光催化材料应用于光电器件及光催化等领域.
In this article,the first principles calculation method is used to study the MoSi_(2)N_(4)/GeC heterostructures,and calculate its structural,electronic,and optical properties.And the effects of different biaxial strains and vertical electric fields on the band structure and optical absorption characteristics of the heterostructures are also investigated.MoSi_(2)N_(4)/GeC heterostructure is an indirect bandgap semiconductor with a bandgap of 1.25 eV,with the built-in electric field direction pointing from the GeC layer to the MoSi_(2)N_(4)layer.In addition,its photogenerated carrier transfer mechanism conforms to the S-type heterostructures mechanism,thus improving the oxidation reduction potential of photocatalytic water decomposition,making it fully meet the requirements of photocatalytic water decomposition with pH=0−14.Under biaxial strain,the band gap first increases and then decreases with the increase of compressive strain,and the light absorption performance in the ultraviolet region increases with compressive strain increasing.The band gap decreases as tensile strain increases,and the light absorption performance in the visible light region is enhanced in comparison with its counterpart under compressive strain.Under a vertical electric field,the band gap increases with positive electric field increasing,and decreases with negative electric field increasing.In summary,MoSi_(2)N_(4)/GeC heterostructures can be used as an efficient photocatalytic material in some fields such as optoelectronic devices and photocatalysis.
作者
赵娜娜
王佳敏
袁志浩
崔真
任聪聪
Zhao Na-Na;Wang Jia-Min;Yuan Zhi-Hao;Cui Zhen;Ren Cong-Cong(School of Materials Science and Engineering,Xi’an University of Technology,Xi’an 710048,China;International Joint Research Center for Intelligent Manufacturing Technology of Composite Materials and Products,Xi’an 710048,China;School of Science,Xi’an University of Technology,Xi’an 710054,China;School of Automation and Information Engineering,Xi’an University of Technology,Xi’an 710048,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第19期195-205,共11页
Acta Physica Sinica
基金
国家自然科学基金(批准号:52274395,U20A20235)
陕西省重点研发计划(批准号:2018ZDXM-GY-139)
中国博士后科学基金(批准号:2018M633542)资助的课题。
关键词
S型异质结
光催化水分解
双轴应变调控
垂直电场调控
S-type heterostructures
photocatalytic water decomposition
biaxial strain regulation
vertical electric field regulation
