Mamidanna Ramachandra Rao1 Dhruba Das1

1, IIT Madras, Chennai, , India

CVD diamond is considered as a new interesting conventional wide bandgap (Eg ~ 5.5 eV) semiconducting material having both n- and p-type dopants, which makes it attractive for numerous applications. For instance, nitrogen has one extra valence electron and thus substituting carbon with nitrogen will make diamond conductive, via the motion of free electrons in the conduction band. However, nitrogen substituting for carbon undergoes a Jahn-Teller distortion which generates a deep donor level at 1.7 eV below the conduction band. Nitrogen–vacancy (NV) defects give diamond a pink hue and arise when a nitrogen atom replaces a carbon atom at a position in the diamond lattice next to a vacant site. These systems are rapidly becoming a front-runner for use as the basic unit of quantum information, the ‘qubit’ in a solid-state quantum computer and have been investigated as solid-state sources of single photons.
Since formation energies of neutral N impurities in diamond is -3.4 eV, it explains the prevalence of N in natural diamond. In the present work, we have employed hot filament chemical vapour deposition (HFCVD) method to create NV centers in diamond. Photoluminescence (PL) studies using excitation wavelength λex = 532 nm reveal the presence of NV- center having zero phonon line (ZPL) at 637 nm along with Silicon-vacancy (Si-V) color center having ZPL at 738 nm.