CALCULATION OF THE FIGURE OF MERIT FOR INDIUM TIN OXIDE-FILMS BASED ON BASIC THEORY

Indium tin oxide (ITO) exhibits some of the most impressive properties such as high electrical conductivity andhigh optical transparency. These qualities have competing mechanisms which give rise to the need for a compromise between the transmission and conductivity. In order to optimize the conductivity and the transmission as a function of doping, it is necessary to determine the figure of merit as a function of the carrier concentration. We have compared different figures of merit as a function of carrier concentration on the basis of basic theoretical concepts instead of experimental values of conductivity and transmission. Estimates of the refractive index (n) and the extinction coefficient (k) aremade and used to predict the optical transmission as a function of the carrier concentration in the films. It appearsthere is an optimum value of doping in ITO thin films. © 1995, American Vacuum Society. All rights reserved.