Tailoring of electroluminescence from n-ZnO/p-GaN heterojunctions

In this study, electroluminescence (EL) from n-ZnO/p-GaN heterojunctions is investigated and tailored. The heterojunctions were obtained by depositing high-quality ZnO films on the p-GaN substrate through pulsed laser deposition (PLD), and the characteristics were analyzed by X-ray diffraction (XRD), photoluminescence (PL) spectra at room-temperature (RT, 300 K), current-voltage (I-V) characteristics curves, and the EL spectra. By means of the band energy theory, a simple and effective way to tailor the luminescent properties of the heterojunction was discussed. The ultra-violet (UV) emission from the n-ZnO was obtained through the improvement of the electrical properties of the films and the substrates. The visible light emissions were tailored through the transition of different defect caused color emissions. Besides, an unexpected yellow light (YL) emission caused by Ga-O interlayer was also studied.