Acta Metallurgica Sinica (English Letters) ›› 2005, Vol. 18 ›› Issue (3): 403-410 .

• Research Articles • Previous Articles     Next Articles

EFFECT OF THE DEFECT STATES DENSITY ON OPTICAL BAND GAP OF CdIn2O4 THIN FILM

H.S.San   

  1. Key Laboratory for Magnetism and Magnetic Material of Ministry of Education,LanzhouUniversity,Lanzhou730000,China
  • Received:1900-01-01 Revised:1900-01-01 Online:2005-06-25 Published:2009-10-10
  • Contact: H.S.San

Abstract: Transparent conducting oxides Cdln2O4 thin films were prepared by radio-frequency reactive sputtering from a Cd-ln aUoy target in Ar+O2 atmosphere. By transmission spectrum and Hall measurement for different samples prepared at different substrate temperatures, it could be found that the carrier concentration would increase with the decrease of substrate temperature, but absorption edge showed an abrupt variation from a blue shift to a red shift. TheoreticaUy, the paper formulated the effect of high-density point defects on band structures; it embodied the formation of band tailing, Burstein-Moss shift and band-gap narrowing. The density of holes will influence the magnitude of optical band gap and transmittance of light. Since extrapolation method does not fit degenerate semiconductor materials, a more accurate method of obtaining optical band gap is curve fitting. In addition, ionized impurities scattering is the main damping mechanism of the free electrons in Cdln2O4 films, the density of ionized impurities induced by altering substrate temperature will affect the carriers mobility.

Key words: sputtering, Cdln2O4 thin film, electrical property