Broadband Circularly Polarized Luminescence with a High Dissymmetry Factor

Materials exhibiting circularly polarized luminescence (CPL) hold great potential for three-dimensional (3D) displays, anticounterfeiting, and optoelectronics. However, research on broadband CPL is still limited. Herein, a Mn^II complex with a green emission band and high quantum yield was synthesized and doped into an EVA matrix to create a luminescent EVA-Mn^II layer. In combination with the cholesteric liquid crystal polymer network (CLCN) film, CPL-active composite films with high |g_lum| values (up to 1.34) were obtained. Furthermore, when a luminescent EVA-Mn^II/EVA-Eu^III layer emitting both red and green fluorescence was stacked with a CLCN film with double reflection bands, high |g_lum| values (|g_lum| > 1) in a broad CPL band range (490-710 nm, Δλ > 200 nm) were achieved. Based on the chiral optical filtering effect of CLCN films, this work not only tuned the CPL handedness and achieved high |g_lum| values but also developed a method for broadband displays and anticounterfeiting.