Effect of Die Shape and Size on Performance of III-Nitride Micro-LEDs: A Modeling Study
AbstractFlip-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. View Full-Text
Share & Cite This Article
Bulashevich, K.A.; Konoplev, S.S.; Karpov, S.Y. Effect of Die Shape and Size on Performance of III-Nitride Micro-LEDs: A Modeling Study. Photonics 2018, 5, 41.
Bulashevich KA, Konoplev SS, Karpov SY. Effect of Die Shape and Size on Performance of III-Nitride Micro-LEDs: A Modeling Study. Photonics. 2018; 5(4):41.Chicago/Turabian Style
Bulashevich, Kirill A.; Konoplev, Sergey S.; Karpov, Sergey Y. 2018. "Effect of Die Shape and Size on Performance of III-Nitride Micro-LEDs: A Modeling Study." Photonics 5, no. 4: 41.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.