Manganese-Doped CsPbBr3 Perovskite LEDs With External Quantum Efficiency Exceeding 22% via Passivated Grain Boundary Engineering

This study investigates external quantum efficiency enhancement and operational stability improvement in Mn2+-doped CsPbBr3 perovskite LEDs via passivated grain boundary engineering within the context of perovskite optoelectronics and semiconductor device engineering, an area of growing scientific importance given its implications for high-efficiency green perovskite LED displays, solid-state lighting, and micro-LED applications. Using spin-coated CsPbBr3:Mn perovskite emitter layers with varied doping and PMMA passivation, characterized by electroluminescence, EQE-current measurement, TRPL, and time-stability testing, we examine Mn2+ dopant suppressing non-radiative recombination at grain boundaries by passivating Pb2+ vacancies and reducing defect density, with PMMA shell further reducing surface quenching pathways in 48 device variants (4 Mn concentrations x 3 passivation treatments x 4 device architectures) with 12 pixels per substrate, n=576 individual device measurements drawn from nitrogen glovebox device fabrication and characterization in integrating sphere with silicon photodiode calibration at Sunrise Institute optoelectronics laboratory. Results indicate that 1.0 mol% Mn-doped CsPbBr3 with PMMA passivation achieves peak EQE of 22.4% at 8 mA/cm2 and T50 of 124 hours at 100 cd/m2, representing a 2.1x EQE and 18x lifetime improvement over undoped reference (p < 0.001), with EQE 22.4%, T50 124 hours; 2.1x EQE and 18x lifetime vs. undoped as the primary quantitative benchmark. Concordance between primary and confirmatory measurement approaches exceeded 93%, validating the analytical framework. These findings contribute empirically to perovskite optoelectronics and semiconductor device engineering and carry actionable implications for the design of programs and policies targeting high-efficiency green perovskite LED displays, solid-state lighting, and micro-LED applications.