Integrating Conjugated Polymers with Bacteriorhodopsin to Realize Quasi Dual-Gate Organic Field-Effect Transistors

Four conjugated polymers are integrated with a bacteriorhodopsin D94N-HmBRI in organic field-effect transistors (OFETs) with the device architecture of doped Si bottom gate/SiO2 bottom electric/semiconducting polymer/Au electrodes/D94N-HmBRI top dielectric. Photosensitivity of D94N-HmBRI in the devices is validated. It is proposed that light activates the conformational change of all-trans retinal to 13-cis retinal in D94N-HmBRI. The D94N-HmBRI layer then applies momentary dipoles to the semiconductors, affecting threshold voltage, resulting in photosensitivity. Film-thickness variation, capacitance determination, and grazing-incidence X-ray scattering are performed to support the proposed working principle. Quasi dual-gate OFETs with a highly doped silicon wafer as the bottom gate and light as the top gate are thus realized by combining conjugated polymers with D94N-HmBRI.