## 4 Conclusions  
In this study, we characterize thin films of conducting oxides, ITO and AZO, before and after proton irradiation. The treatment is meant to simulate the cosmic space environment. XRD characterization proved that no structural changes were induced by the 226.5 MeV proton beam at a fluence of 10\({}^{11}\) cm\({}^{-2}\). Microscopic observations with SEM showed that ITO did not change with irradiation, whereas on the surface of AZO, new defects and larger precipitates emerged. Using mapping spectroscopic ellipsometry, we observe that proton irradiation made both oxides less homogenous. XPS analysis clearly shows that irradiation was more impactful for AZO than ITO. Proton irradiation caused more defects and deterioration in AZO. All components in AZO shifted to higher binding energy, which indicates an increase in electrical resistance. While the transmittance and resistance of ITO did not change much, in the case of AZO, the transmittance increased, and the resistance decreased after irradiation. A higher number of defects could be the reason for improved conductivity, as in the case of oxide semiconductors, their conductivity depends on the presence of defects such as oxygen vacancies and metallic interstitials. Higher AZO conductivity corresponds to analysis of optical properties with spectroscopic ellipsometry, where the extinction coefficient behaviour indicates an increase in the free carriers number. The contradiction between XPS and sheet resistance measurements may be due to a different depth of the material being probed. In the case of XPS, only a few nanometres of surface are explored, while electrodes in the four-point probe measurement can penetrate the surface. \begin{table}
\begin{tabular}{c c} \hline
**Sample** & **Sheet Resistance [\(\Omega\)/\(\square\)]** \\ \hline AZO & 302.485 \(\pm\) 3.413 \\ AZO: H+ & 202.347 \(\pm\) 0.265 \\ ITO & 9.106 \(\pm\) 0.001 \\ ITO: H+ & 9.266 \(\pm\) 0.010 \\ \hline \end{tabular}
\end{table} 
Table 2: Sheet resistance of studied samples. This research shows that the high-energy proton environment has a slight negative influence on the properties of transparent conductive oxide thin films, proving they are good candidates as functional layers in space applications. Conceptualization--K.U., K.W.M. and J.R.; data curation--K.U., J.R., A.E.B. and D.A.P. ; formal analysis--K.U., A.E.B. and J.R.; funding acquisition--[PERSON], A.E.B. and A.C.G. ; investigation--[PERSON], [PERSON], [PERSON] and D.A.P. ; methodology--[PERSON], [PERSON] and J.R.; project administration--[PERSON], [PERSON] and A.C.G. ; resources--[PERSON], [PERSON], J.R., D.A.P., K.W.M. and A.C.G. ; software--[PERSON] and A.E.B. ; supervision--[PERSON] and A.C.G. ; validation--[PERSON], [PERSON] and K.W.M. ; visualization--[PERSON], [PERSON], [PERSON] and A.E.B. ; writing--original draft--[PERSON] and [PERSON]; writing--review and editing--[PERSON], D.A.P. and A.C.G. All authors have read and agreed to the published version of the manuscript. Research project funded partly by the \"Excellence Initiative--Research University\" program for the AGH University of Krakow, and AGH University of Krakow Project no. 16.16.230.434. NIMP authors acknowledge funding from the Romanian Ministry of Research, Innovation and Digitalization through the Core Project PC3-PN23080303 and UEFISCDI PN-III-P4-ID-PCE-2020-0827 (Contract no. PCE74 09/02/2021) project. Not applicable. The data presented in this article are available at [[https://doi.org/10.58032/AGH/NTW5J4](https://doi.org/10.58032/AGH/NTW5J4)]([https://doi.org/10.58032/AGH/NTW5J4](https://doi.org/10.58032/AGH/NTW5J4)) or at request from corresponding author. X-ray diffraction measurements were performed in the Department of Silicate Chemistry and Macromolecular Compounds of the Faculty of Materials Science and Ceramics at the AGH University of Krakow. The XPS measurements were performed using the Romanian National Interest Setup \"System of complex XPS/ESCA installations and research using synchrotron radiation\".