Rational Design of All-Inorganic Assemblies with Bright Circularly Polarized Luminescence

Adv Mater. 2023 Feb;35(7):e2209539. doi: 10.1002/adma.202209539. Epub 2022 Dec 19.

Abstract

Materials with exceptional circularly polarized luminescence (CPL) are important in multi-field applications such as 3D display, anti-counterfeiting, sensing, spin electronics, etc. Although CPL properties have been widely investigated ranging from the traditional chiral organic molecules to the emerging chiral inorganic nanomaterials and their assemblies, a trade-off between the luminescence efficiency (quantum yield, ϕ) and the luminescence dissymmetry factor (glum ) is always the bottleneck for all the chiral luminescent materials, which hinders their practical application. Herein, a new route to overcome the paradox through rationally assembling quantum nanorods and ultrathin inorganic nanowires into ordered multilayer structures is reported, achieving both high ϕ and glum . In these assembled structures, the aligned quantum nanorods emit linearly polarized light that is then transformed to CPL by the aligned ultrathin nanowire assemblies with precisely controlled phase retardation. This method is universal and readily extended to versatile 1D nanomaterials, paving the way for the practical applications of CPL active materials.

Keywords: Langmuir-Schaefer assembly; birefringence; circularly polarized luminescence; inorganic nanowires; quantum nanorods; quarter-wave plate.