Multiphysics Model Unravels the Efficiency and Radiance Roll-Off in Perovskite Light Emitting Diodes

Despite their excellent performance, perovskite light emitting diodes (PeLEDs) are limited by efficiency roll-off under high injection conditions. Although often attributed to Joule heating and Auger recombination, efficiency roll-off is not fully quantitatively explained, which hampers further device optimization. Here, through a multiphysics approach, we provide a consistent explanation for several key characteristics of PeLEDs. Our model explains the dark JV characteristics, EQE (external quantum efficiency), ECE (energy conversion efficiency), and radiance roll-off in PeLEDs. Remarkably, our results identify a previously unexplored positive feedback mechanism that involves temperature dependent radiative recombination as the dominant cause for efficiency roll-off. Our proposed model could be of broad interest as it explains the characteristics of PeLEDs with a broad range of band gaps, identifies performance limiting factors, and suggests optimization pathways.