Design of a Horizontally Aligned Perovskite Nanowire LED With Improved Light Extraction

Within a short span of a few years, metal halide perovskite light-emitting diodes (LEDs) have shot past the 20 percent external quantum efficiency mark. As the material quality and photoluminescent quantum yield of perovskite are already at par with the state-of-the-art, light extraction for further quantum efficiency enhancement has taken the center stage of scientific interest. Herein, we demonstrate horizontally aligned perovskite nanowire-based light-emitting diodes with 50.9 percent of light extraction efficiency, with a 2.9-fold increase compared to the planar counterpart. The absorption spectra of the plane wave incidence exhibit the weak trapping of light within the emission range. Purcell factors of horizontal perovskite nanowires with different diameters are also studied, which provides design guidelines for applying the horizontally aligned perovskite nanowires for multifarious optoelectronic applications such as lasing. The resonance peak positioned at 530 nm wavelength shows the nanowire antennas’ effect in the nanowires with diameters of 300 nm, 500 nm, and 550 nm respectively. Furthermore, the fabrication process of the light-emitting devices based on ink-jet printing has also been proposed. This report not only provides an in-depth understanding of light extraction in nanowire LEDs but also heralds the inception of horizontally aligned perovskite nanowire-based optoelectronic devices.