Fabrication and field emission characteristic of microcrystalline diamond/carbon nanotube double-layered pyramid arrays

• Microcrystalline diamond (MCD) carbon nanotube (CNT) composite's been fabricated.
• MCD/CNT double-layered pyramid arrays have been fabricated.
• MCD/CNT double-layered pyramid arrays' turn-on electric field is about 2.84 V/μm.
• MCD/CNT double-layered pyramid arrays' field emission lifetime is over 100 h.
• This study provides a simple and more economical method to grow CNT on MCD.

In this study, microcrystalline diamond (MCD)/carbon nanotube (CNT) double-layered pyramid arrays have been fabricated by microwave plasma chemical vapor deposition (MPCVD). First, the silicon template with pyramidal cavity arrays was manufactured using photolithography with anisotropic wet-etching. MCD film was then grown on the silicon template by MPCVD. After the sol–gel catalyst which contains ferric nitrate, tetrabutyl titanate and n-propanol was spun on the MCD film, CNT film was grown by MPCVD. In order to etch away the silicon template, hydrofluoric acid and nitric acid are used for 2 h. From the results, the turn-on electric field of MCD/CNT double-layered pyramid arrays is about 2.84 V/μm and lifetime over 100 h.