Stabilization of an Electric-Field-Induced Microscale (2 μm) Perovskite Light-Emitting Diode via Defect Engineering

The miniaturization of perovskite light-emitting diodes (PeLEDs) to single-pixel dimension below 10 µm represents a critical challenge for next-generation high-definition displays. Conventional photolithography techniques face fundamental compatibility issues with perovskite materials, while the stability and efficiency of microscale devices are compromised by defect-mediated non-radiative recombination and ion migration effects at reduced dimensions. This work demonstrates a significant advancement in microscale PeLED performance through synergistic optimization of precursor stoichiometry and surface passivation engineering. By employing guanidinium bromide (GABr) as a multifunctional passivator, we achieved simultaneous bulk and surface defect suppression with the formation of a stabilizing 2D/3D heterostructure. The optimized 2 µm PeLED devices exhibited remarkable performance enhancements, achieving a peak external quantum efficiency of 7.4%, current efficiency of 42.3 cd/A, and luminance of 4.6 × 10⁴ cd/m². More importantly, the operational service lifetime was extended two orders of magnitude from 3 to 271 s, addressing the fundamental stability limitations that have previously hindered practical applications. This work provides an alternative fabrication pathway that circumvents the size constraints of conventional microfabrication processes, enabling the development of high-performance microscale light-emitting devices for augmented reality, virtual reality, and other advanced display technologies that require ultrahigh pixel densities.