Photoluminescence study of nitrogen-doped p-type Mg_xZn_(1-x)O nanocrystalline thin film grown by plasma-assisted molecular beam epitaxy

摘要

Temperature-dependent photoluminescence of nitrogen-doped p-type Mg_xZn_(1-x)O nanocrystalline thin film grown on c-plane sapphire substrate by rf plasma-assisted molecular beam epitaxy is investigated. P-type behavior is confirmed by both Hall effect and Seebeck measurements. Structural defect-related bound excitonic emission peak is distinguished at around ～ 50 meV lower than peak energy of the near band edge neutral acceptor bound excitonic emission. Typical 'S shape' behavior of energy position versus temperature is observed due to polarization-induced internal field. Nitrogen-related acceptor ionization energy is calculated to be ～ 180-200 meV.