Micro-light-emitting diodes （Micro-LEDs） with high brightness， high contrast， low energy consumption and fast response and other excellent characteristics， are widely used in outdoor display， augmented reality and virtual reality and other fields. However， the miniaturization of Micro-LEDs brings challenges to the control of light intensity distribution. In order to improve its luminous efficiency， patterned sapphire substrate （PSS） technology is often used to optimize the light extraction efficiency through micron-scale patterned structures. In large-size LEDs， PSS has a small effect on the spatial distribution of light intensity， but it has a significant effect in micro-level LEDs. In this paper， the ray tracing method is employed to systematically study the spatial distribution of light intensity in PSS Micro-LEDs of different sizes， with an emission wavelength of 460 nm， under various array offsets. The spatial asymmetry of the light intensity distribution is also quantified. The results show that as the size decreases， the influence of PSS on the spatial distribution of light intensity increases. When the size is 3 μm×5 μm， the asymmetry of the spatial distribution of light intensity reaches 3.06% on the y-axis and 4.22% on the x-axis， thus affecting the luminous uniformity of the Micro-LED. This study provides theoretical support for the optimal design of Micro-LEDs in display applications.

micro-LED;patterned sapphire substrate（PSS）;asymmetry ratio