Preparation,Structural Characterization,Optical And Electrical Properties Of Te Base Semiconductor Materials Research With Chalcopyrite Structure

The rare earth semiconductor compounds CuIn1-xRxTe2(R=Eu,Sm),Cu2ZnSnSe4,Cu2Zn1-xCexSnTe4 were synthesized by vacuum arc melting and vacuum solid state reaction in muffle furnace.X-ray diffraction(XRD),Scanning electron microscope(SEM),Energy disperse spectroscopy(EDS),Ultraviolet and visible spectrophotometer(UV-Vis)were used to investigate their crystal structures,the surface's morphology,elementary composition and optical properties.The diffraction peaks and patterns were analyzed by internal center diffraction data PDF cards,TEROR indice and Rietveld structure refinement technology.The results show that CuIn1-xRxTe2(R=Eu,Sm)compounds with single phase have been successfully synthesized.For the semiconductor compound of CuIn1-xEuxTe2,the lattice parameters are a=6.189(8)-6.191(2)A and c=12.405(6)-12.409(1)A.The Scanning electron microscope(SEM)morphologies show that the europium doping into CuIn1-xEuxTe2 can fine the grains from the largely agglomerated state to the uniformly separated state.The electrical resistivities of single phase CuIn1-xEuxTe2 follow a mixture model of hopping conductivity and variable range hopping conductivity.The absorption band-gaps of CuIn1-xEuxTe2 at room temperature tend to increase with increasing Eu content.CuIn1-xEuxTe2 might be a good candidate for photovoltaic cell.Then for the semiconductor compound of CuIn1-xSmxTe2,the lattice parameters are a=6.189(5)-6.193(8)and c=12.401(0)-12.409(7)A.Two phases have been detected in Cu2ZnSnSe4,the main phase has a body tetragonal structure with a space group of I-42m.The anther phase is Cu3Se2 with a space group of P-421m.The lattice parameters are a=6.418(2)A and c=4.206(4)A.Cu2Zn1-xCexSnTe4 crystallines in tetragonal structure with a space group of I-42m of main phase.The lattice parameters are a=6.054(3)-6.096(2)A and c=12.079(1)-12.137(5)A.The atomic occupations in one unit cell are corresponding to the 4d(0,0.5,0.25)site for Cu atoms,the 2a(0,0,0)site for Zn and Ce atoms,the 2b(0,0,0.25)site for Sn atoms and the 8i(x,x,z)site for Te atoms.