The Structures And Preparations Of The B-Si Codoped Diamond Films

In order to investigate the effect of B-Si co doping on the crystal structure and electronic structure of diamond films,the formation energy of B-Si Co doped diamond grains and the preparation of B-Si Co doped diamond films were studied by first principles calculation and MPCVD experiment.In the aspect of theoretical calculation,the formation energy and energy band of Si replacement doping,B replacement doping and B-Si co doping diamond,the formation energy of Si replacement doping and B replacement doping diamond with different valence states and concentrations,the formation energy of B replacement doping and B-Si co doping diamond with different vacancy,and the dissociation energy of boron doped diamond with 1.61% boron are calculated respectively by using the first principle calculation method.The formation energy and energy band of B-substituted doping into silicon carbide(SIC)are calculated.In the aspect of experimental preparation,based on the preparation of diamond films on the substrate pretreated with nano seed solution,B-Si Co doped diamond films were prepared with tetramethylsilane and ethoborane as doping sources,and characterized by atomic force microscopy(AFM),scanning electron microscopy(SEM).Through calculation and experiment,the following results are obtained:The results show that boron atoms can be substituted into diamond grains.When boron atoms are added into diamond,the indirect band gap will be changed into direct band gap,and p-type semiconductor characteristics will be displayed.It is difficult for silicon atoms to enter diamond grains in CVD process.When boron silicon Co doped diamond films grow,two phases of diamond and silicon carbide may appear,and boron atoms tend to enter the diamond phase.The experimental results show that the boron silicon Co doped diamond films can be prepared by chemical vapor deposition(CVD).The results show that silicon doped diamond films show that silicon doping does have the effect of nano diamond grains,andboron has a strong crystallization strengthening effect.Excessive boron doping will lead to the increase of the grain size and the roughness of the doped diamond films.