Field-Effect Transistors on Photonic Cellulose Nanocrystal Solid Electrolyte for Circular Polarized Light Sensing

The integration of bioinspired chiral cellulose nanocrystal (CNC) films into transistor devices with distinct sensing properties for left- and right-handed circular polarized light (LCPL and RCPL, respectively) is reported. The CNC films with a left-handed internal long-range order are infiltrated with sodium ions to yield solid-state electrolytes with photonic properties capable of LCPL reflection and RCPL transmission. They are employed as gate dielectrics in sputtered amorphous indium–gallium–zinc oxide (a-IGZO) transistors. The obtained devices operate in depletion mode at low voltages (<2 V) with On–Off ratios of up to 7 orders of magnitude, subthreshold swings around 80 mV dec⁻¹, and saturation mobilities up to 9 cm² V⁻¹ s⁻¹. Combining the photonic character of the CNC films with the light sensitivity of a-IGZO, the devices are capable of discrimination between LCPL and RCPL signals in the blue region. These type of devices can find application in photonics, emission, conversion, or sensing with CPL but also imaging or spintronics.