Perovskite light-emitting diodes (PeLEDs) have emerged as a promising candidate for next-generation display technologies due to their exceptional optoelectronic properties. These materials exhibit high color purity, tunable emission across the visible spectrum, and compatibility with low-cost solution-processing techniques. Unlike organic light-emitting diodes (OLEDs) or quantum dot LEDs (QLEDs), PeLEDs leverage the unique electronic structure of perovskite semiconductors, which combine efficient charge transport with narrow emission linewidths.
One of the most compelling advantages of PeLEDs is their high color purity, characterized by full-width-at-half-maximum (FWHM) values as low as 20 nm. This narrow emission results in superior color gamut coverage, exceeding the Rec. 2020 standard for high dynamic range displays. The tunability of emission wavelengths is achieved through compositional engineering of the perovskite structure, typically by adjusting halide ratios in lead-based perovskites (e.g., CsPbX3, where X = Cl, Br, I). Mixed halide compositions enable precise control over bandgap energies, facilitating emission from deep blue to near-infrared wavelengths.
Solution-processability is another key advantage, as PeLEDs can be fabricated using spin-coating, inkjet printing, or blade-coating techniques. This contrasts with vacuum-deposited OLEDs and high-temperature processed QLEDs, reducing manufacturing complexity and cost. Recent advances in precursor ink formulations have enabled the deposition of uniform, pinhole-free perovskite films with high photoluminescence quantum yields (PLQYs) exceeding 90%.
Despite these advantages, PeLEDs face significant challenges, particularly in material stability. Under electrical bias, halide perovskites are prone to ion migration, leading to phase segregation and spectral shifts in mixed-halide devices. This phenomenon is exacerbated at higher voltages, limiting operational lifetimes. Additionally, environmental factors such as moisture, oxygen, and thermal stress accelerate degradation, necessitating advanced encapsulation strategies.
Recent breakthroughs in efficiency have pushed PeLED performance closer to commercial viability. External quantum efficiencies (EQEs) exceeding 28% have been reported for green-emitting PeLEDs, rivaling state-of-the-art OLEDs and QLEDs. These improvements stem from optimized charge injection layers, defect passivation techniques, and nanostructured perovskite emitters. For instance, the introduction of multifunctional organic ligands has reduced non-radiative recombination losses, while interfacial engineering has minimized energy barriers between transport layers.
Comparing PeLEDs with OLEDs and QLEDs reveals distinct differences in material properties and device physics. OLEDs rely on organic molecules with inherently broader emission spectra, requiring complex cavity designs or color filters to achieve high color purity. In contrast, PeLEDs intrinsically emit narrowband light due to their excitonic nature. QLEDs, while also capable of narrow emission, depend on expensive colloidal quantum dots with stringent surface chemistry requirements. PeLEDs offer a middle ground, combining the solution-processability of polymers with the high performance of inorganic semiconductors.
Operational stability remains a critical hurdle for PeLED commercialization. While OLEDs achieve lifetimes exceeding 10,000 hours, PeLEDs currently lag behind due to ion migration and electrochemical reactions at interfaces. Strategies such as dimensionality engineering—incorporating 2D/3D perovskite heterostructures—have shown promise in suppressing ion diffusion. Similarly, the use of inorganic charge transport layers has improved device robustness under prolonged operation.
Looking ahead, the scalability of PeLED manufacturing presents opportunities for large-area displays and flexible electronics. Roll-to-roll processing of perovskite films could enable low-cost production of ultra-high-definition screens. However, consistency in film morphology and defect control across large substrates remains a technical challenge. Advances in ink formulation and deposition techniques will be crucial to address these issues.
In summary, PeLEDs represent a disruptive technology in the display industry, offering unparalleled color purity, tunability, and cost-effective fabrication. While stability and efficiency challenges persist, recent material innovations and device optimizations have significantly narrowed the performance gap with established technologies. Continued research into interfacial engineering, ion migration suppression, and scalable processing will determine the commercial trajectory of PeLEDs in next-generation displays.