The paper presents a comprehensive approach to enhance the performance of AlGaN-based deep-ultraviolet (DUV) light-emitting diodes (LEDs) operating in the 210–280 nm spectral range, which has potential applications in physical sterilization. The authors address the significant challenge of poor external quantum efficiency (EQE) by combining bandgap engineering and device craftsmanship. They introduce tailored multiple quantum wells (MQWs), a reflective Al reflector, a low-optical-loss tunneling junction (TJ), and a dielectric SiO2 insertion structure (IS-SiO2). These innovations result in an outstanding light output power (LOP) of 1401 mW at 850 mA, with EQEs 4.5 times higher than conventional LEDs. The study overcomes major difficulties such as strong quantum-confined Stark effect (QCSE), severe optical absorption in the p-electrode/ohmic contact layer, and poor transverse magnetic (TM)-polarized light extraction. Electroluminescence (EL) characterization on the wafer scale validates the scalability of the DUV LEDs for large-scale production. The work demonstrates a promising strategy for developing highly efficient AlGaN-based DUV LEDs, with potential applications in biomedical testing, water/air purification, and other fields.The paper presents a comprehensive approach to enhance the performance of AlGaN-based deep-ultraviolet (DUV) light-emitting diodes (LEDs) operating in the 210–280 nm spectral range, which has potential applications in physical sterilization. The authors address the significant challenge of poor external quantum efficiency (EQE) by combining bandgap engineering and device craftsmanship. They introduce tailored multiple quantum wells (MQWs), a reflective Al reflector, a low-optical-loss tunneling junction (TJ), and a dielectric SiO2 insertion structure (IS-SiO2). These innovations result in an outstanding light output power (LOP) of 1401 mW at 850 mA, with EQEs 4.5 times higher than conventional LEDs. The study overcomes major difficulties such as strong quantum-confined Stark effect (QCSE), severe optical absorption in the p-electrode/ohmic contact layer, and poor transverse magnetic (TM)-polarized light extraction. Electroluminescence (EL) characterization on the wafer scale validates the scalability of the DUV LEDs for large-scale production. The work demonstrates a promising strategy for developing highly efficient AlGaN-based DUV LEDs, with potential applications in biomedical testing, water/air purification, and other fields.