We present a spectroscopic investigation of molecular nitrogen using a self-resonating co-axial dielectric barrier plasma reactor. The properties of the nitrogen plasma generated were recorded as functions of radio frequency (27.12 MHz), power (20–50W) and gas pressure (0.1–60mbar). The intensity distribution of the transitional structure of the electronic bands 𝐶3Π𝑢 → 𝐵3Π𝑔, 𝐵2Σ+ 𝑢 → 𝑋2Σ+ 𝑔 and 𝐷2Π𝑔 → 𝐴2Π𝑢 was measured as a function of gas pressure. Relative energy efficiency (total emitted intensity from the plasma 𝐼𝑡 divided by total electric power to the discharge 𝑃), as high as 14% can be obtained at a dissipated electrical power level of 20W and a pressure of 10mbar.