Circularly polarized light detection by a chiral organic semiconductor transistor

Abstract

Circularly polarized light is central to many photonic technologies, including circularly polarized ellipsometry-based tomography1,2, optical communication of spin information3 and quantum-based optical computing and information processing4,5. To develop these technologies to their full potential requires the realization of miniature, integrated devices that are capable of detecting the chirality or ‘handedness’ of circularly polarized light. Organic field-effect transistors, in which the active semiconducting layer is an organic material, allow the simple fabrication of ultrathin, compact devices6,7,8. Here we demonstrate a circularly polarized light-detecting organic field-effect transistor based on an asymmetrically pure, helically shaped chiral semiconducting molecule known as a helicene9. Importantly, we find a highly specific photoresponse to circularly polarized light, which is directly related to the handedness of the helicene molecule. We believe that this opens up the possibility for the detection of the chirality of circularly polarized light in a highly integrated photonic platform. An organic field effect transistor featuring the chiral molecule helicene acts as a photodetector that is able to distinguish between left- and right-handed circularly polarized light.