Optical and Electrical Properties ofCd2SnO4: A Defect Semiconductor

${\mathrm{Cd}}_2$Sn${\mathrm{O}}_4$ has been found to be an $n$-type defect semiconductor in which oxygen vacancies provide the donor states. Crystalline powders and amorphous films with a wide range of conductivities have been prepared. Large Burstein shifts have been observed in the visible reflection and transmission spectra. Analysis of electrical and optical data on thin amorphous films of ${\mathrm{Cd}}_2$Sn${\mathrm{O}}_4$ leads to a calculated optical band gap of 2.06 eV, a charge-carrier mobility of 10-20 ${\mathrm{cm}}^2$/V sec, and an effective mass 0.04 of the free-electron mass. The conductivity of amorphous films can be made as great as 1.33×${10}^3$ ${\mathrm{\Omega }}^{-1\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$, retaining high visible transmittance.