High-Performance Organic Narrow Dual-band Circular Polarized Light Detection for Encrypted Communications And Color Imaging.

Conventional circularly polarized light (CPL) detectors necessitate several optical elements, posing difficulties in achieving miniature and integrated devices. Recently developed organic CPL detectors require no additional optical elements but usually suffer from low detectivity or low asymmetry factor (g-factor). Here, an organic CPL detector with excellent detectivity and a high g-factor is fabricated. By employing an inverted quasi-planar heterojunction (IPHJ) structure and incorporating an additional liquid crystal film, we develop a CPL detector with an outstanding g-factor of 1.62. Unfavorable charge injection is effectively suppressed by the IPHJ structure, which reduces the dark current of the organic photodetector. Consequently, a left CPL detectivity of 6.16 × 10 14 Jones at 640 nm is realized, surpassing all of the latest photodiode-type CPL detectors. Adopting a liquid crystal film with adjustable wavelengths of selectively reflected light, the hybrid device achieved narrow dual-band CPL detection, varying from 530 nm to 640 nm, with a half-maximum full width below 90 nm. Notably, the device achieves excellent stability of 260000 on/off cycles without attenuation. To the best of our knowledge, all these features have rarely been reported in previous work. The CPL detector arrays are also demonstrated for encrypted communications and color imaging. This article is protected by copyright. All rights reserved.