Among all the materials, carbon nanostructures have garnered the attention of researchers and technologists over the last few decades due to their versatile applications in a wide range of fields. Fullerene, carbon nanotube, nanofibers, nanocoil, etc., have already established their importance in different fields, but still, day after day, new novel carbon nanostructures are being discovered and find their applications. The element carbon is unique in the sense that it has a wide variety of allotropes with a fascinating range of mechanical, optical, and electrical properties. Among all the fields mentioned above, carbon fibers, tubes, coils, diamond-like carbon, diamond, graphene, and even amorphous carbons have established themselves as very good field emitters and are used in different related applications, especially in field emission displays.