Quantitative measure of nitrogen vacancy related effects in SmN and EuN*

Muhammad Azeem

Abstract

Density of charge carriers, introduced due to nitrogen vacancies, is estimated for SmN and EuN thin films. SmN is found to be weakly doped by nitrogen vacancies with an estimated carrier density of the order of 10²⁴−10²⁵ m⁻³ whereas the EuN thin film is heavily doped with the carrier density of the order 10²⁷ m⁻³. The free carriers cause the significant optical absorption in the sub-gap region and mask the true energy gap. Further, the onset of the interband transition for the SmN is around 1.2 eV and for the EuN it is 0.9 eV. The results indicate a disagreement in the theoretical and the experimental values