Increasing Efficiency and Extending Lifetime of Red Micro Light-Emitting Diodes Through Sidewall Treatment for Improved Reliability

The micro light-emitting diodes (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>LEDs) offer advantages that make it an attractive option for various applications, such as displays, lighting, AR/VR, and consumer electronics. The light output power (LOP) and external quantum efficiency (EQE) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>LEDs are the crucial parameters that impact the performance and suitability of these devices. Ongoing studies are focused on addressing the issue of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>LEDs. In this study, we propose several treatment strategies to modify the sidewall of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>LEDs and improve the performance of devices. The results show that the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>LEDs treated with citric acid (CA) and ammonium sulfide [(NH<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{4}}\text {)}_{{2}}$ </tex-math></inline-formula>Sx] for 1 h have the best improvement in LOP by 93.3%, and EQE increases by 91.3%. In addition, the reliability of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>LEDs with different sidewall treatments was studied under long-term aging and high-temperature and high-humidity conditions. The treatment method for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>LEDs has made significant contributions to the performance of devices, bringing about advancements in various key areas.