Experimental Evidence on Stability of N Substitution for O in ZnO Lattice

Although the dispute remains, the N substitution for the lattice O (N_O) in zinc oxide (ZnO) demonstrates the promising future in achieving the p-type ZnO-based semiconductor. In this context, a highly crystallized N-doped ZnO (ZnO:N) film is fabricated with ultralow defect density. Based on the synchrotron radiation X-ray absorption near-edge structure (XANES) and low-temperature photoluminescence (PL) spectra combined with first-principles calculations, the results demonstrate that the majority of N ions locate stably at the lattice O site to succeeding the N substitution for lattice O as the N_O defects. A prototype LED device is built based on the homojunction of ZnO:N film and ZnO:Ga wafer with good electroluminescence performance. These important findings provide a rewarding avenue to the p-type ZnO semiconductor design and device fabrication, and demonstrate a prevailing guidance on the materials design and development as well.