Summary: | In order to achieve high quantum efficiency of AlGaN-based deep ultraviolet light-emitting diodes (UVC-LED), it is important to improve the light extraction efficiency (LEE). In this paper, theoretical simulation and experiment of SiO<sub>2</sub> anti-reflective film deposited on UVC-LED were investigated. The effect of different SiO<sub>2</sub> thickness on the light extraction efficiency of 275 nm UVC-LED was studied, showing that 140 nm SiO<sub>2</sub> anti-reflective film can effectively improve the light output power of UVC-LED by more than 5.5%, which were also confirmed by the TFCALC simulation. The enhancement of UVC-LED light extraction efficiency by this antireflective film is mainly due to the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfrac bevelled="true"><mrow><mn>3</mn><mi mathvariant="sans-serif">λ</mi></mrow><mn>2</mn></mfrac></mrow></semantics></math></inline-formula> light coherent effect at the SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> interface. Our work proved the promising application of antireflective coating on UVC-LED.
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