Investigation of the Sn4+ Charge Density Variation in In2O3 using Mössbauer Spectroscopy

Thin tin‐doped indium oxide films have a low resistivity and they find an application as electrodes in flat panel displays, solar cells, etc. A number of publications were devoted to investigate ITO powders with diffe‐rent Sn content and ITO films subjected to oxidizing and reducing annealing. Similar investigations on the ITO films prepared by reactive magnetron sputtering at elevated substrate temperatures are missing up to now. Therefore indium‐tin oxides (ITO) films were deposited by reactive middle frequency dual magnetron sputtering at heated substrates. The doping of Sn in In2O3 was investigated using the surface sensitive 119mSn Conversion Electron Mossbauer Spectroscopy (CEMS) to investigate the chemical state of tin. Changes of the Mossbauer parameters like isomer shift (δ), integral intensity ratio (IIR) and the quadrupole splitting (Δ) are shown.