Abstract

Tin oxide (TO), F-doped SnO2 (FTO), and Eu/F-codoped SnO2 (EFTO) films were deposited by spray pyrolysis. Additionally, for the DFT calculations, different superstructures were considered as models for TO (SnO2), FTO (Sn36O21F), and EFTO (EuSn35O70F2). Electrical and optical measurements showed that the EFTO films maintain the characteristics of a transparent conducting oxide (TCOs), i.e., high optical transparency and low electrical resistivity (rho). The plasma wavelength for EFTO thin films was red-shifted when compared to FTO, which is related to the diminishing of free electron density (n(e)) and the increase of rho; such effects were promoted by the incorporation of Eu impurities which act as electron acceptors. Photoluminescence (PL) studies revealed that the EFTO films did not show electronic transitions related to Eu states in the visible part of the spectra (vis). On the other hand, the DFT calculations confirmed the experimental results related to the incorporation of Eu/F impurities in TO, such as cell expansion, the creation of direct bandgap TCOs, the appearance of the Burstein-Moss effect, the absence of emission lines in the vis, and the diminishing of n e due to the presence of Eu acceptor states.