The First Principles Calculation And Doping Modification Study On Electronic Structure Of P-Cu₂O

Cu₂O is popular with researchers.Due to the existence of Cu vacancy and O inter stitial in Cu₂O,the ionization energy approximately achieve 0.4eV.The carriers' s conce ntration in room temperature is as l-ow as 10¹² 10¹⁴cm^-3,which is the main reason for limiting its application.In this paper,optical properties of pure/Cu₂O,Ag/Cu₂O,Cl/Cu₂O,Ce/Cu₂O,NCl/Cu₂O,Ge-Sn/Cu₂O and the forming energy,electron density of pure/Cu₂O?110?,Al/Cu₂O?110?,In/Cu₂O?110?and so on were calculated using the first-principles plane wave ultrasoft pseudo-potential method based on the density functional theory.The resul ts are approximately described below:Cu₂O has good ultraviolet and visible light absorption properties;After Ag is substituted for Cu,the Ag and Cu are present in a monovalent manner,and the optical properties are similar to those when they are not doped,so the photocatalytic performance is not improved obviously;When the Cl dopant reaches a sufficient concentration,the introduction of the shallow donor level enhances the carrier concentration and enhances the absorption capacity of Cu₂O;Although the Ce/Cu₂O bandgap width becomes larger,but the Fermi level through the conduction band,so that Ce/Cu₂O has some metallic properties.The formation of two shallow donor levels reduces the recombination probability of photogenerated electrons and holes and improves the photocatalytic capacity.The optical absorption band of N-Cl/Cu₂O appeared blue shift;Ge/Cu₂O,Sn/Cu₂O,Ge-Sn/Cu₂O three-doped system Fermi level into the conduction band,changing the characteristics of Cu₂O P-type semiconductor,it has the characteristics of N-type semiconductor.The relative electron concentration of the conduction band of Ge-Sn/Cu₂O is improved,which is beneficial to improve the conductivity.The pure/Cu₂O?110?surface energy is 4.12eV/nm2,and this value is small,indicating that Cu₂O?110?surface is relatively easy to form;In the In/Cu₂O?110?system: In atoms are more likely to bind to O in Cu₂O,and the formation of In/Cu₂O?110?is more stable than pure pure/Cu₂O?110?.After doping the band is slightly larger,because the change is very small,little effect on the light absorption;The stability of the Al/Cu₂O?110?system is better than pure/Cu₂O?110?,and it is also better than In/Cu₂O?110?.The dielectric function of theAl/Cu₂O?110?indicates that the electrons bound to the Al3+ will break away from the potential barrier to continue the reciprocating motion,resulting in relaxation and loss;The results of CO molecules adsorbed on Cu₂O?110?show that: Adsorption energy is large,indicating that CO adsorption on Cu₂O?110?surface is more stable;The electron density of the?110?plane is increased,and the adsorption of CO effectively increases the activity of Cu₂O?110?plane.