Deep level defects in a nitrogen-implanted ZnO homogeneous p-n junction

Nitrogen ions were implanted into undoped melt grown ZnO single crystals. A light-emitting p-n junction was subsequently formed by postimplantation annealing in air. Deep level transient spectroscopy was used to investigate deep level defects induced by N+ implantation and the effect of air annealing. The N+ implantation enhanced the electron trap at E-C-(0.31 +/- 0.01) eV (E3) and introduced another one at E-C-(0.95 +/- 0.02) eV (D1), which were removed after annealing at 900 and 750 degrees C, respectively. Another trap D2 (E-a = 0.17 +/- 0.01 eV) was formed after the 750 degrees C annealing and persisted at 1200 degrees C.