Ultrathin CsPbX₃ Nanowire Arrays with Strong Emission Anisotropy

Abstract

1D nanowires of all-inorganic lead halide perovskites represent a good architecture for the development of polarization-sensitive optoelectronic devices due to their high absorption efficient, emission yield, and dielectric constants. However, among as-fabricated perovskite nanowires with the lateral dimensions of hundreds nanometers so far, the optical anisotropy is hindered and rarely explored owing to the invalidating of electrostatic dielectric mismatch in the physical dimensions. Here, well-aligned CsPbBr and CsPbCl nanowires with thickness T down to 15 and 7 nm, respectively, are synthesized using a vapor phase van der Waals epitaxial method. Strong emission anisotropy with polarization ratio up to ≈0.78 is demonstrated in the nanowires with T < 40 nm due to the electrostatic dielectric confinement. With the increasing of thickness, the polarization ratio remarkably reduces monotonously to ≈0.17 until T ≈140 nm; and further oscillates in a small amplitude owing to the wave characteristic of light. These findings not only represent a demonstration of perovskite-based polarization-sensitive light sources, but also advance fundamental understanding of their polarization properties of perovskite nanowires.

Controlled Synthesis and Photonics Applications of Metal Halide Perovskite Nanowires

“…Furthermore, the perovskite NW array detector showed anisotropic optical absorption, which was employed to achieve polarization‐sensitive photodetection with a high polarization ratio of 2.6:1 (Figure h). The anisotropic optical behaviors of perovskite NWs were also confirmed by Gao et al In their work, through decreasing the diameter of CsPbX 3 NWs, the strong emission anisotropy was observed with polarization ratio up to ≈0.78. These 1D perovskites NWs represented a good architecture for the development of polarization‐sensitive optoelectronic devices.…”

Lead‐Free Double Perovskite Cs2SnX6: Facile Solution Synthesis and Excellent Stability

“…Organic–inorganic lead halide perovskites have recently been intensively investigated due to their superior optoelectronic and photovoltaic characteristics. Since their pioneering application in solar cells with an efficiency of 3.8% in 2009, researchers have made great efforts to further develop metal halide perovskites in various applications such as field‐effect transistors, solar cells, photodetectors, thermoelectrics, tandem devices, light‐emitting electrochemical cells, diodes, and laser . Despite the rapid growth of the organic–inorganic lead halide perovskite research efforts in both academia and industry, two biggest challenges still remain and hinder their widespread applications.…”

Catalyst‐Free and Morphology‐Controlled Growth of 2D Perovskite Nanowires for Polarized Light Detection

“…We also reveal that the emission from the nanowires is highly dependent on the incoming polarization of the incident light owing to anisotropic absorption of the nanowires. The polarization ratio is found to be as high as 0.73, one of the largest reported for perovskites . Finally, we fabricate a hybrid (C 4 H 9 NH 3 ) 2 PbI 4 /graphene/hybrid device and demonstrate its application as a polarization photodetector with photocurrent anisotropy ratio of 3.62.…”