Analyzing UV/Vis/NIR Spectra—Addition of Oxygen and Nitrogen to ZnO:Al Thin-Films II—Effective Dopant Concentration, Mobility and Lifetime

Exact optical analysis of aluminum doped zinc-oxide (ZnO:Al) thin-films have been shown in [1], as function of reactive O₂-and inert N₂-gas additions to the inert Ar process-gas. Here, a theoretical model is introduced, which allows the determination of typical semiconductor parameters, by use of UV/Vis/NIR spectroscopy-a contact-free measurement method. In detail, effective dopant concentrations, n_e, in semiconducting thin-films, as well as mobilities, μ, drift velocities, v_D, lifetimes, τ, and mean free paths, I, of electrons within these layers can be calculated. Sputtered aluminum-doped zinc-oxide (ZnO:Al) thin-films have been analysed with respect to reactive oxygen additions to the inert argon process-gas and with respect to substrate-temperatures. The effects of these two parameters on the above mentioned physical values have been investigated and discussed.