Fully Chiral Light Emission from CsPbX₃ Perovskite Nanocrystals Enabled by Cholesteric Superstructure Stacks

Abstract

Halide perovskites have received tremendous attention due to their fantastic optical and electrical properties. Here, circularly polarized light emission is successfully demonstrated using a simple configuration consisting of inorganic perovskite nanocrystals embedded within a predefined handedness cholesteric superstructure stack. The helical structured cholesteric liquid crystal film acts as a selective filter to transform the unpolarized light emission from perovskite nanocrystals into circularly polarized luminescence. The transformation is accompanied by an extraordinary dissymmetry factor (|g lum |) up to 1.6, well-defined handedness, high photoluminescence quantum yield, and full-color availability. Furthermore, the circularly polarized luminescence is angular dependent and can easily be modulated by shifting the overlap of the reflection band and the emission band. The proposed method is more straightforward and powerful than the previous approaches, offering new opportunities in optoelectronic and photonic devices.of turning the unpolarized light emission arising from the perovskite NC layer into fully chiral light emission with a high dissymmetry factor value of ≈1.6. To the best of our knowledge, this is one of the highest values reported for the dissymmetry factor of circularly polarized light emission from perovskite materials.

Polarization‐Sensitive Halide Perovskites for Polarized Luminescence and Detection: Recent Advances and Perspectives

“…After that, circular-polarization-sensitive luminescence and detection based on low-dimensional chiral perovskite have been widely reported. [46][47][48] Herein, we give a comprehensive review on the recent progress in the field of polarization-sensitive HPs. We begin with the discussion of the principles of polarized luminescence and detection, including linear polarization and circular polarization.…”

“…Recently, Wang et al. [ 48 ] realized full‐color CPL of CsPbX 3 film b2y using a cholesteric superstructure stack strategy. As shown in Figure a, the CsPbX 3 NCs layer was embedded between two cholesteric liquid crystals (CLCs) filter layers with opposite helical handedness.…”

“…After that, circular‐polarization‐sensitive luminescence and detection based on low‐dimensional chiral perovskite have been widely reported. [ 46–48 ]…”

Status and Outlook of Metal–Inorganic Semiconductor–Metal Photodetectors

“…These emerging material‐based MSM‐PDs show impressive performances due to their excellent optoelectronic properties. [ 15–21 ] Most importantly, the perovskite layers can be fabricated through solution processes, which can significantly reduce the device cost. [ 22–26 ] The research status of the MSM‐PDs has undergone great changes in recent years, due to the development of these new materials, and a relevant review is urgently needed.…”

Stability of Perovskite Light Sources: Status and Challenges

“…[ 1‐5 ] In recent years, solution‐processed semiconductors have achieved rapid progresses due to their high‐performance and low‐cost compared with the commercially available semiconductors such as silicon and gallium arsenide. [ 6–32 ] Especially, perovskites, a group of the most promising candidates, [ 33–39 ] have already shown superior performances in many applications including solar cells, light sources, and photodetectors, [ 40–46 ] attributed to their exceptional optoelectronic properties such as large charge carrier diffusion length, long carrier lifetime, high quantum yield efficiency, and good wavelength tunability. [ 47 ] Moreover, perovskites have shown great potential in solid‐state‐light sources and are supposed to be an effective way to realize solution‐processed laser diodes.…”