Antireflection coatings based on fluoride formulations for organic solar cells

An alloy of a mixture of fluorides MgF$_{2}$ and AlF$_{3}$ with CaF$_{2}$ has been obtained in a 3-kW solar furnace. It was supposed that a minor CaF$_2$ additive compensates for the tensile stresses appearing in thin MgF$_{2}$ and AlF$_{3}$ films, with their mechanical properties being thereby improved. The results of X-ray phase analysis demonstrated that both components of the mixture are present in the alloy, while the complex oxide CaAl$_{4}$O$_{7}$, the formation of which is attributed to the melting in air, is only identified in AlF$_{3}$: CaF$_2$ = 95: 5 (wt %). The increase in the transmittance of glass and polyethylene terephthalate upon deposition onto their surface of a thin film of the material synthesized in the study is due to the optical properties of AlF$_{3}$ and MgF$_{2}$.