Patent attributes
A diamond electron emission element is provided with a substrate, and a plurality of quadrangular columns (microscopic projections) composed of diamond and with side faces of flat faces, which are arranged at equal intervals on the substrate. A top end face (horizontal section) is of a quadrangular shape having a length of long sides being a [nm] and a length of short sides being ka [nm], and a thin film of SiO2 is formed on a side face on the short-edge side. The length a [nm] of long sides and the length ka [nm] of short sides satisfy relational expressions of Formulae (1) and (2) below.C1=2a√{square root over (1+k2)} (1)nλ=C1 (2)C1: a distance [nm] of a lap in a situation where light generated inside each quadrangular column goes around on a specific circuit while being reflected on the side faces of the quadrangular column,n: an arbitrary positive integer, andλ: an emission peak wavelength λ [nm] of the diamond making the quadrangular columns.
