Multicolor chiral perovskite nanowire films with strong and tailorable circularly polarized luminescence
Fang Peng, Dan Liang, En Yang, Bongjun Yeom, Yuan Zhao, Wei Ma
Abstract
Perovskites showcased potential promise for innovative circularly polarized luminescence (CPL)-active multichannel information encryption, owing to the exceptional luminescence brightness. It was still a formidable challenge to fabricate CPL-active perovskites with significant luminescent asymmetry factor ( g lum ) and full-colour-tailorable CPL properties. Indeed, compared to isotropic perovskites, anisotropic perovskite nanowires (NWs) were conducive to carrier separation and transport for polarization enhancement. Herein, three types of CsPb(Br/I) 3 NWs with green, orange, red fluorescence (FL) were respectively synthesized and assembled into chiral NW films. The right-handed/left-handed chiral NW films constructed by 4+4 layers and 45° inter-angles exhibits highly symmetric and mirror-like chiral signals. The strongest chiral intensity is more than 3000 medg. CPL signals with wide colour gamut produce ranging from 480 nm to 800 nm, and tailorable CPL wavelengths are manipulated by the emission wavelength of perovskite NWs. A giant CPL signal with a maximum g lum of up to 10 −1 is achieved. The polarization imaging of chiral NW films produces brilliant differential circularly polarized structural colours, making it more widely used in multilevel anti-counterfeiting systems. A significant breakthrough lies in the development of advanced chiral perovskite materials with remarkable g lum and tailorable CPL properties, which sheds new light on optical anti-counterfeiting and intelligent information encryption. Perovskite NWs engineered chiral films were firstly self-assembled and generated mirrorlike chiral signals with the values of >3000 mdeg. Perovskite NW films displayed intensive and multicolor circularly polarized luminescence signals in the range of 480 nm–800 nm. Remarkable g lum values of ±0.1 (10 −1 ) were obtained. Chiral perovskite NW films achieved the applications in multilevel intelligent information encryption.