Photoluminescent Properties of Erbium-Doped Aluminum Scandium Nitride Thin Films

Abstract

Scandium (Sc)-doped aluminum nitride (AlN) (Al_1–xSc_xN) has attracted increasing attention in integrated photonics due to its remarkable piezoelectric, electro-optic, and acousto-optic properties. Erbium (Er)-doped Al_1–xSc_xN presents promising opportunities for the development of high-gain integrated optical amplifiers and high-efficiency lasers in silicon photonic applications. However, research on the photoluminescent (PL) properties of Er-doped Al_1–xSc_xN films remains limited. In this work, the PL properties of Er-doped Al_1–xSc_xN films are investigated systematically across different Er and Sc concentrations. Strong PL emission at communication wavelengths was observed at room temperature. The PL intensity of the Er-doped Al_0.904Sc_0.096N sample is more than five times higher than that of the Er-doped AlN sample with the same Er doping concentration under identical excitation conditions. Additionally, the PL intensity of the Er-doped Al_0.904Sc_0.096N sample remained nearly constant as the temperature increases from 77 to 300 K, indicating a significantly suppressed thermal quenching effect. Notably, the 0.3% Er-doped Al_0.904Sc_0.096N sample exhibited a PL intensity up to 70 times higher than that of the commercially available 0.5%Er-doped lithium niobate on the insulator sample, demonstrating a strong potential for applications in integrated optical amplifiers and lasers on silicon photonic platforms.