Preparation And Characteristics Of SiC-based Graphene/Ge Heterojunction

Silicon carbide?SiC?is consider as an ultraviolet light control devices due to the high wide bandgap and the high absorption in ultraviolet light region.However,SiC is not sensitive to visible light and near infrared light,which limiting its application in the field of non-ultraviolet light area.Therefore,a low pressure chemical vapor deposition of germanium?Ge?film with preferred orientation on the 4H-SiC substrate is introduced as light absorption layer,and the wet transferred or dry transferred graphene onto the Ge film to form the SiC-based graphene/Ge heterojunction.The conclusions as follows:1.The SiC/Ge heterojunction has been prepared by LPCVD method with the growth temperature of 850?and the flow rates of H₂ and GeH₄ is 100?20?unit:sccm?.The grain size of Ge film and the crystal surface spacing are 9.05nm and 0.11nm,respectively.2.The dry transferred and the wet transferred graphene quality was analyzed by Ra-man spectra and scanning electron microscope.et al.The Raman peak intensity I_G/I_D and I_2D/I_G of dry transferred and wet transferred graphene are 7.3 and 1.5,5.8 and 2.2,repectively.The Raman results indicate the dry tranferred graphene with less cracks and disloctations is obtained.3.The optical transmission property of SiC-based graphene/Ge heterojunction indi-cated the light absorption with a transmittance is lower than 15%in 500nm-1200nm region which proves the Ge film has play the important role in the heterojunction.4.The SiC-based graphene/Ge heterojunction has well rectifying characteristic in darkness.The photo-generated current of the heterojunction is 0.147?A/cm² under the0.1W/cm² input light.And we preliminary reached photoelectric response of heteojunction.