HIGH MOBILITY AND HIGHLY TRANSPARENT CERIUM DOPED INDIUM OXIDE FILMS DEPOSITED BY MAGNETRON SPUTTERING FOR PHOTOVOLTAIC APPLICATIONS

Abstract

One of the primary sources of optical losses in solar cells is the parasitic free carrier absorption of sunlight in TCOs, which significantly affects their transparency in the near-infrared (NIR) region. Therefore, TCOs with high mobility and moderate carrier concentration are desirable as possible substitutes to ITO for photovoltaic applications.

This thesis investigates the material properties of magnetron sputtered cerium-doped indium oxide (ICeO) thin films as functions of various sputtering growth parameters, including substrate temperature, oxygen content, sputtering power and Ar flow rate. The highest mobility obtained for ICeO in this thesis is 71 cm2/Vs, which is more than two times higher than that previously reported with magnetron sputtering of ITO: Ce films and more than three times of that obtained for standard ITO films in this work. Moreover, neutral impurity scattering is the most dominant scattering mechanism in ICeO films, with the predominant oxidation state of cerium being +3.