Formation of luminescence spectra and emission intensity in the UV and visible spectral regions for $n$-ZnO/$p$-GaN and $n$-ZnO/$p$-ZnO structures when depositing ZnO films by high-frequency magnetron sputtering

The emission spectra of structures based on ZnO films deposited by high-frequency magnetron sputtering are studied. Clearly pronounced emission lines associated with the recombination of free ($\lambda$ = 363 nm) and bound excitons ($\lambda$ = 377, 390, 410 nm) are observed in the PL (photoluminescence) spectra ($T$ = 300 K) of $n$-ZnO/$p$-GaN:Mg structures, and no substantial emission is observed in the impurity PL region $\lambda$ = 450–600 nm. Only emission lines characteristic of $n$-ZnO ($\lambda$ = 374 nm) are observed in the EL (electroluminescence) spectra of $n$-ZnO/$p$-ZnO structures ($T$ = 300 K).