CC BY-NC 3.0 UnportedPan, XuanzhaoZhao, JiangboQian, GujieZhang, XiaozhouRuan, YinlanAbell, AndrewEbendorff-Heidepriem, Heike2022-05-102022-05-102020https://oa.tib.eu/renate/handle/123456789/8924https://doi.org/10.34657/7962The development of amorphous films with a wide transmission window and high refractive index is of growing significance due to the strong demand of integrating functional nanoparticles for the next-generation hybrid optoelectronic films. High-index TeO2-based glass films made via the sol-gel process are particularly suitable as their low temperature preparation process promises high compatibility with a large variety of nanoparticles and substrates that suffer from low thermal stability. However, due to the lack of in-depth understanding of the mechanisms of the formation of undesired metallic-Te (highly absorbing species) in the films, the preparation of high-transmission TeO2-based sol-gel films has been severely hampered. Here, by gaining insight into the mechanistic chemistry of metallic-Te formation at different stages during the non-hydrolytic sol-gel process, we identify the chemical route to prevent the generation of metallic-Te in a TeO2-based film. The as-prepared TeO2-based film exhibits a high transmission that is close to the theoretical limit. This opens up a new avenue for advancing the performance of hybrid optoelectronic films via incorporating a large variety of unique nanoparticles. © 2020 The Royal Society of Chemistry.enghttps://creativecommons.org/licenses/by-nc/3.0/540Amorphous filmsGlassNanoparticlesRefractive indexSol-gel processTellurium compoundsTemperatureFunctional nanoparticlesHigh refractive indexHigh transmissionIn-depth understandingLow temperature preparationNonhydrolytic sol-gel processTheoretical limitsTransmission windowFilm preparationArticle