General trends in scaling dimensions of a circular‐shaped flip‐chip light‐emitting diode (LED) are studied by coupled electrical‐thermal‐optical simulations. Advanced chip design is considered, providing high efficiency of light extraction through the top surface of the LED die. The simulation model accounts for such important effects, as current crowding near metallic electrodes, thermal and non‐thermal efficiency droop caused by Auger recombination, and surface recombination at the edges of the LED active region. Interplay and competition of the mechanisms is demonstrated in a wide range of operating current densities and chip dimensions varied from tens to hundreds of micrometers. It is shown that surface recombination, which is especially important in small‐size LEDs, is the major mechanism controlling evolution of the LED characteristics under the chip size variation. The impact of surface recombination on LED characteristics is predicted to weaken at high current densities typical for operation of micro‐LEDs due to shortening of carrier life time in the active region. Advantages of micro‐LEDs are discussed on the basis of the simulations.

Flip-chip truncated-pyramid-shaped blue micro-light-emitting diodes (μ-LEDs), with different inclinations of the mesa facets to the epitaxial layer plane, are studied by simulations, implementing experimental information on temperature-dependent parameters and characteristics of large-size devices. Strong non-monotonous dependence of light extraction efficiency (LEE) on the inclination angle is revealed, affecting, remarkably, the overall emission efficiency. Without texturing of emitting surfaces, LEE to air up to 54.4% is predicted for optimized shape of the μ-LED dice, which is higher than that of conventional large-size LEDs. The major factors limiting the μ-LED performance are identified, among which, the most critical are the optical losses originated from incomplete light reflection from metallic electrodes and the high p-contact resistance caused by its small area. Optimization of the p-electrode dimensions enables further improvement of high-current wall-plug efficiency of the devices. The roles of surface recombination, device self-heating, current crowding, and efficiency droop at high current densities, in limitation of the μ-LED efficiency, are assessed. A novel approach implementing the characterization data of large-size LED as the input information for simulations is tested successfully.

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Numerical simulation of a quantum well on nitrides, optical interband transitions in low dimensional semiconductor structures (semiconductor quantum wells), conduction-heavy hole and transitions in quantum wells, refinement of the gain for a quantum well on nitride materials with allowance for the overlap integral and approximate this.

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