Application of printed nanocrystalline diamond film for electron emission cathode

The low-cost and large area screen-printed nano-diamond film (NDF) for electronic emission was fabricated. The edges and corners of nanocrystalline diamond are natural field-emitters. The nano-diamond paste for screen-printing was fabricated of mixing nano-graphite and other inorganic or organic vehicles. Through enough disperse in isopropyl alcohol by ultrasonic nano-diamond paste was screen-printed on the substrates to form NDF. SEM images showed that the surface morphology of NDF was improved, and the nano-diamond emitters were exposed from NDF through the special thermal-sintering technique and post-treatment process. The field emission characteristics of NDF were measured under all conditions with 10−6 Pa pressure. The results indicated that the field emission stability and emission uniformity of NDF were improved through hydrogen plasma post-treatment process. The turn-on field decreased from 1.60 V/μm to 1.25 V/μm. The screen-printed NDF can be applied to the displays electronic emission cathode for low-cost outdoor in large area.

Research highlights▶ A kind of diamond paste was developed by mixing nanodiamond powder with nanocrystalline graphite. ▶ The best proportion of the mixture with nano-graphite and nano-diamond and ethylic cellulose was 2:5:6. ▶ The nanocrystalline diamond emitters were exposed from the NDF uniformly with best proportion and after three-steps sintering and hydrogen plasma treatment process. ▶ Treatment process would make nanodiamond emission tip sharper and distribution uniformly, and enable the electron to tunnel in the film, and make electron emit easier, and enhance electron emission uniformity and stability.