Direct detection of circular polarized light in helical 1D perovskite-based photodiode

Ishii and Miyasaka, Sci. Adv. 2020; 6 : eabd3274 11 November 2020 SCIE N C E A D V A NCES | RESEA R CH A RT ICL E 1 of 6 M A T E RIALS SCIENC E Direct detection of circular polarized light in helical 1D perovskite-based photodiode A. Ishii1,2* and T. Miyasaka1* Detection of circularly polarized light (CPL) has a high potential for development of various optical technologies. Conventional photodetectors require optical polarizers on the device to detect polarized light, and this causes substantial losses of sensitivity and resolution in light detection. Here, we report direct CPL detection by a photo- diode using a helical one-dimensional (1D) structure of lead halide perovskites composed of naphthylethylamine-­ based chiral organic cations. The 1D structure with face-sharing (PbI6)4− octahedral chains whose helicity is largely affected by chiral cations shows intense circular dichroism (CD) signals over 3000 mdeg at 395 nm with the highly anisotropy factor (gCD) of 0.04. This high CD enables photocurrent detection with effective discrimination between left-handed and right-handed CPLs. The CPL detector based on this 1D perovskite achieved the highest polarization discrimination ratio of 25.4, which largely surpasses the direct detecting CPL devices (<4) using chiral plasmonic metamaterials and organic materials. INTRODUCTION In transaction of optical information, main functions of light source are intensity, color (wavelength), and polarization. Polarization of light can be used for object identification, contrast enhancement, navigation, and communication through polarizing reflections (1–3). This function also has a high potential for application in various optical technologies and