A new approach to synthesising highly uniform, highly transmissive nanocrystalline diamond films for display protection

Nanocrystalline and ultra-nanocrystalline diamond films have high transmittance, high hardness, excellent thermal conductivity, and wear resistance, which make them excellent surface protection materials, but the high uniformity synthesis technology of nanocrystalline diamond has been limited by the growth of high uniformity nucleation, and has not been able to be applied on a wide scale. With the development of wearable devices and mobile device display technology, the demand for display cover protection has gradually increased. In this thesis, high uniformity and high transmittance nanocrystalline diamond films were prepared by firstly using physical vapour deposition of a layer of ta-C (tetrahedral amorphous carbon) thin film, and then synthesizing nanocrystalline diamond films by plasma treatment. The transmittance of the nanocrystalline diamond films can reach more than 95% in the visible near-infrared, and more than 90% in the ultraviolet band (UVC to UVA). The most effective treatment is ta-C film under hydrogen plasma for 10 min, and the resulting nanocrystalline diamond grain size is about 5~20 nm. This study helps to promote the application of nanocrystalline diamond films and diamond-like films in the field of display covers and other applications.